CN101171353A - Ferritic stainless steel sheet for original pipe of bellows - Google Patents
Ferritic stainless steel sheet for original pipe of bellows Download PDFInfo
- Publication number
- CN101171353A CN101171353A CNA2006800148642A CN200680014864A CN101171353A CN 101171353 A CN101171353 A CN 101171353A CN A2006800148642 A CNA2006800148642 A CN A2006800148642A CN 200680014864 A CN200680014864 A CN 200680014864A CN 101171353 A CN101171353 A CN 101171353A
- Authority
- CN
- China
- Prior art keywords
- quality
- stainless steel
- steel sheet
- following
- ferrite stainless
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Landscapes
- Heat Treatment Of Sheet Steel (AREA)
Abstract
A ferrite stainless steel sheet for bellows stock pipe that simultaneously attains excellent workability and excellent high-temperature properties (high-temperature salt erosion resistance and high-temperature fatigue performance). In particular, there is provided a ferrite stainless steel sheet for bellows stock pipe comprising 0.015 mass% or less C, 1.0 mass% or less Si, 1.0 mass% or less Mn, 0.04 mass% or less P, 0.010 mass% or less S, 11 to 19 mass% Cr, 0.015 mass% or less N, 0.15 mass% or less Al, 1.25 to 2.5 mass% Mo, 0.3 to 0.7 mass% Nb, 0.0003 to 0.003 mass% B and the balance Fe and unavoidable impurities. In preferred form, there is provided a ferrite stainless steel sheet for bellows stock pipe whose average crystal grain diameter (D) is 35 mum or less, or whose surface roughness in terms of Ra is 0.40 mum or less.
Description
Technical field
The present invention relates to be used for the ferrite stainless steel sheet (ferritic stainless steel sheet) of bellows stock pipe (raw material pipe for bellows pipe), particularly good, simultaneously high temperature fatigue characteristic (high-temperature fatigueproperties), the good ferrite stainless steel sheet for bellows stock pipe of high temperature salt damage corrosive property (high-temperature salt corrosion) of workability (formability).
Background technology
In the mechanism of treatment liq, gas or powder etc., normally carry out its conveying by the metal pipe arrangement.And, common centre at this pipe arrangement, the strain (strain), the stress (stress) that cause for the thermal expansion (thermal expansion) of the vibration that absorbs mechanism, pipe arrangement, and relax its influence, setting has the metal tubulation (accordion steel pipe) of the accordion-like of parallel wave mode wall (parallel corrugated wall), i.e. corrugated tube (also being called metal hose (flexibletubing)).
In the past, as the former material that is used for corrugated tube, mainly used the FCC metal (face centeredcubic metal) as representative with copper, SUS304 (austenitic stainless steel (austenitic stainless steel)) etc.Its reason is, is difficult to be processed into corrugated tube with other metallic substance.Promptly, because copper, austenitic stainless steel plate, unit elongation, n value (n-value) near the normal temperature (room temperature) are bigger than other metallic substance, thereby are suitable for the bulge forming (bulge forming) of requirement tensile properties (elongationcharacteristic).
But, the austenitic stainless steel plate, though be processed into corrugated tube easily, but under corrodibility such as gas that passes through bellows interior or liquid strong situation or pyritous situation, there is the problem that is easy to generate oxidation (oxidization), high temperature corrosion (high-temperature corrosion) or stress corrosion cracking (stress corrosion crack).Particularly, the corrugated tube of austenitic stainless steel plate system that is used for the connection portion (coupling parts) of automobile exhaust pipe (automotive exhaust pipe), because the temperature (service temperature) in using rises to about 500～750 ℃, be dispersed under the situation of the salt on the road adhering to because of snow melt (snow melting) thus, also there is the sensitization (sensitization) that becomes of former material itself, thereby causes the problem of high temperature salt damage corrosion (high-temperature salt corrosion) easily.
From this background, various ferrite stainless steel sheet for bellows stock pipe have been invented out.For example, open in the flat 7-268560 communique the spy, disclose and a kind ofly reach the ferrite stainless steel sheet of the corrugated tube excellent processability of unit elongation more than 35% and 1.5 above r values by C, Si, Mn, S, Cr, Al, Ti, N, O gauge being decided to be specified range.And, open in the flat 8-176750 communique the spy, disclose a kind ofly by C, Cr, Al, N, Si, Mn, Ti, Nb, Mo, Cu, Ni gauge are decided to be specified range, and the crystallization particle diameter is limited to optimal scope and the ferrite stainless steel sheet of the corrugated tube excellent processability that obtains.And, open in the flat 8-188854 communique the spy, disclose a kind of by C, Cr, Al, N, Si, Mn, Ti, Nb, Mo, Cu, Ni gauge being decided to be the corrugated tube processibility that specified range obtains and the ferrite stainless steel sheet of high temperature fatigue characteristic good.And, open in the flat 9-125208 communique the spy, disclose a kind ofly by C, Cr, N, Ti, Mo gauge are decided to be specified range, and the surfaceness of former material is limited to optimal scope and the corrugated tube processibility and the good ferrite stainless steel sheet of high temperature salt damage corrodibility that obtain.
But, even utilize above-mentioned technology, with the corrugated tube processibility (bellows formability) of ferrite stainless steel sheet as the former pipe of former material, also still insufficient when comparing with the former pipe that forms by the austenitic stainless steel plate, truth is that the ferrite stainless steel sheet for bellows stock pipe that can be applied to the shape higher than the high H of tooth of corrugated tube can not be provided.At this, the high H of the tooth of corrugated tube is meant as shown in Figure 6,1/2nd of the difference of the crest portion external diameter of corrugated tube (outside diameter ofpeak) Φ and tooth bottom external diameter (outside diameter of bottom) A (outer diameter A of the former pipe of ripple).And, the viewpoint that improves from the fuel consumption of automobile, the hot properties (high-temperature properties) (high temperature salt damage corrodibility, high temperature fatigue characteristic) that requires in the automotive exhaust system component (automotive exhaust system material) etc., have severe gradually cruel trend, the ferrite stainless steel sheet that has good processibility when satisfying described characteristic is developed in strong request.
Summary of the invention
The object of the present invention is to provide a kind of ferrite stainless steel sheet for bellows stock pipe, have good corrugated tube processibility and excellent high-temperature characteristic (high temperature resistant salt damage corrosion and high temperature fatigue characteristic) simultaneously.
Invention is gone into etc., in order to reach above-mentioned purpose, is conceived to one-tenth as the ferrite stainless steel sheet of the former material of bellows stock pipe and is grouped into and has carried out research with keen determination.It found that, the processibility of bellows stock pipe, can improve by the B that in as the ferrite stainless steel sheet of former material, adds trace, on the other hand, the hot properties of high temperature salt damage corrodibility and high temperature fatigue characteristic, can improve by compound interpolation an amount of Nb and Mo, Given this finish the present invention.
Promptly, ferrite stainless steel sheet for bellows stock pipe of the present invention, it is characterized in that, contain that C:0.015 quality % is following, Si:1.0 quality % following, Mn:1.0 quality % is following, P:0.04 quality % is following, S:0.010 quality % is following, Cr:11～19 quality %, N:0.015 quality % are following, Al:0.15 quality % is following, Mo:1.25～2.5 quality %, Nb:0.3～0.7 quality %, B:0.0003～0.003 quality %, surplus is made of Fe and unavoidable impurities.
Stainless steel plate of the present invention is characterized in that, except mentioned component is formed, also contains and is selected among Cu:0.1～0.6 quality %, Ni:0.1～0.6 quality % and the Co:0.03～0.6 quality % more than a kind or 2 kinds.
And, stainless steel plate of the present invention, it is characterized in that, except mentioned component is formed, also contain and be selected among V:0.04～1.0 quality %, W:0.04～5.0 quality %, Ta:0.04～1.0 quality % and the Ti:0.02～1.0 quality % more than a kind or 2 kinds.
And stainless steel plate of the present invention is characterized in that, is used for thickness of slab below 0.5mm, and the outer diameter A of bellows stock pipe is the individual layer of 28～80mm φ or the former pipe of double-deck automobile exhaust system corrugated tube.Wherein, at this, the outer diameter A of bellows stock pipe is the external diameter of the steel pipe before forming corrugated tube, and roughly the tooth bottom outer diameter A with corrugated tube is identical.
And stainless steel plate of the present invention is characterized in that, the average crystallite particle diameter of above-mentioned stainless steel plate is below 35 μ m.
And stainless steel plate of the present invention is characterized in that, the surface roughness Ra of above-mentioned stainless steel plate is below 0.4 μ m.At this, above-mentioned surface roughness Ra is to use the contact surface roughness measurement device according to JIS B0651, according to JIS B0601 (version in 1997), and the value of the arithmetic average roughness Ra of the rectangular direction of rolling direction of mensuration and steel plate.
Ferrite stainless steel sheet of the present invention, (uniform elongationproperties) is higher for uniform elongation, has excellent characteristic such as high temperature salt damage corrosive property, high temperature fatigue characteristic.Therefore, with the bellows stock pipe of ferrite stainless steel sheet of the present invention,, thereby be applicable to the bellows stock pipe that in automobile exhaust system, uses because processibility and hot properties are good as former material.
Description of drawings
Fig. 1 is the figure of expression B content to the influence of uniform elongation generation.
Fig. 2 is the figure of expression Nb content to the influence of high temperature salt damage depth of corrosion and the generation of the high temperature fatigue limit.
Fig. 3 is the figure of expression Mo content to the influence of high temperature salt damage depth of corrosion and the generation of the high temperature fatigue limit.
Fig. 4 is the figure of expression average crystallite particle diameter to the influence of uniform elongation generation.
Fig. 5 is the figure of expression steel surface roughness Ra to the influence of uniform elongation generation.
Fig. 6 is the synoptic diagram of the hydroforming method of explanation 1 tooth forming mode.
Label declaration
1: the bellows stock pipe
2: bar (rod)
3: clamping die (clamp die)
4: shaping die (forming die)
5: gasket (seal packing)
6: shaping tooth (formed peak)
Φ: crest portion external diameter
A: tooth bottom external diameter (external diameter of bellows stock pipe)
H: tooth height
Embodiment
Corrugated tube (bellows) carries out hydraulic pressure bulge forming (hydraulic bulge forming) to the former pipe of piped (untreated pipe) usually and makes.Fig. 6 is used to schematically show the hydroforming method of 1 tooth forming mode.Be specially following method: the 1st, the former pipe of corrugated tube, after it is disposed as Fig. 6, in former pipe, pressurize behind the full of liquid, thereby the tube wall of former pipe is expanded between clamping die 3 and shaping die 4, then, form tooth 6 by clamping die 3 is axially compressed, repeat this operation and make corrugated tube with a plurality of teeth.This method, compare with the method for making the tooth of stated number by a hydroforming, though metal pattern expense cheapness, but there is the lower problem of productivity, but because available fairly simple metal pattern is processed, can freely make number, the tooth height H of tooth, thereby have the advantage of the corrugated tube that can form desirable shape, tooth number.Therefore, as the desired characteristic of former material of former pipe, think that tensile properties, particularly uniform elongation (uniform elongationproperties) (consistent unit elongation) characteristic is important.This be because, even when causing nonaffine deformation (nonuniformity deformation) at a place, hydraulic pressure (fluid pressure) rises and becomes the starting point (source) of crackle (crack) partly, in addition, for example, even do not cause crackle, also can obviously reduce life-span as corrugated tube.Contriver etc., about various ferrite stainless steel sheets, utilize the corrugated tube forming test (bellowsforming test) of hydraulic pressure bulge forming and use the tension test of JIS13 B test film, and investigation can form the high Hmax of molar (difference of the crest portion external diameter of corrugated tube and tooth bottom external diameter 1/2nd) of corrugated tube and the relation between the uniform elongation in the tension test (tensile test).In its result, not finding has tangible mutual relationship between two characteristics.
And, make the shape of tension test sheet various variations take place and measure uniform elongation, and investigate this uniform elongation and can form relation between the high Hmax of molar of corrugated tube.Its result find to use the uniform elongation that the tension test sheet of special shape of length 25mm of width 150mm, the parallel portion of the parallel portion (parallel portion) of tension test sheet measures and can form between the high Hmax of molar of corrugated tube to have mutual relationship.This is illustrated in the broad process zone, even a place produces nonaffine deformation, also with the mutual relationship that is processed with of the corrugated tube that causes crackle, can estimate the corrugated tube processibility by the measuring method of even extensibility.
And contriver etc. have investigated the influence of various interpolation elements to the uniform elongation generation of ferrite stainless steel sheet.Wherein, the experiment to the interpolation B that confirmed to improve effect describes.
Experiment 1
Melting out the basal component with C:0.08 quality %-Si:0.41 quality %-Mn:0.3 1 quality %-P:0.03 quality %-S:0.003 quality %-Cr:14.5 quality %-Al:0.03 quality %-N:0.01 quality %-Nb:0.47 quality %-Mo:1.35 quality % in the laboratory mode forms, and the steel that B content is changed in the scope of 0.0001～0.0040 quality %, after making steel ingot, after this steel ingot being carried out 1170 ℃ * 1 hour heating, carry out hot rolling and make the hot-rolled sheet that thickness of slab is 3.5mm, then, after carrying out 1070 ℃ * 30 seconds annealing, carry out cold rolling and make the cold-reduced sheet that thickness of slab is 0.4mm.On this cold-reduced sheet, implement 1030 ℃ * 30 seconds annealing and after making cold rolled annealed plate, from this cold rolled annealed plate, choose the tension test sheet (parallel portion width: 150mm, parallel portion length 25mm) of above-mentioned special shape abreast with rolling direction, for measuring uniform elongation in tension test.
Fig. 1 is used to represent the influence of the B content of above-mentioned tension test to the uniform elongation generation.As can be seen from Figure 1, by containing the B more than the 0.0003 quality %, can obtain higher uniform elongation, promptly improve the corrugated tube processibility, but contain under the situation of B surpassing 0.0030 quality %, on the contrary, uniform elongation reduces.Though be not the reason of knowing above-mentioned B effect fully, think that this is owing to B produces the element that grain boundary segregation improves grain-boundary strength, thereby under the situation of adding the above B of 0.0003 quality %, the generation of fine crack in the crystal boundary when suppressing distortion.And, the reduction of the uniform elongation when adding B above 0.0030 quality % is thought because because a large amount of borides are separated out in the interpolation of excessive B on crystal boundary, interface between this boride and matrix (matrix) generates small crackle, thereby causes the reduction of uniform elongation.
Then, for the hot properties (high temperature salt damage corrosive property, high temperature fatigue characteristic) that improves ferrite stainless steel sheet, investigate the influence of various interpolation elements.Wherein, the experiment of having confirmed effect is described.
Melting out the basal component with C:0.01 quality %-Si:0.31 quality %-Mn:0.34 quality %-P:0.03 quality %-S:0.005 quality %-Cr:16 quality %-Al:0.018 quality %-N:0.01 quality %-Mo:1.45 quality %-B:0.0006 quality % in the laboratory mode forms, and after making the steel that Nb content changes and make steel ingot in the scope of 0.19～0.74 quality %, after this steel ingot being carried out 1170 ℃ * 1 hour heating, carry out hot rolling and make the hot-rolled sheet that thickness of slab is 3.5mm, then, after carrying out 1070 ℃ * 30 seconds annealing, carry out cold rolling and make the cold-reduced sheet that thickness of slab is 0.4mm.This cold-reduced sheet is implemented 1030 ℃ * 30 seconds annealing and made cold rolled annealed plate (cold-rolled and annealed steel sheet), and supply in following high temperature salt damage corrosion test and fatique testing at elevated temperature.
High temperature salt damage corrosion test
After the test film of cold rolled annealed plate surface and end face ground with No. 400 sand paper (emery paper), dipping is 5 minutes in the saturated aqueous common salt (saturated saline) (the 26%NaCl aqueous solution) of normal temperature, after in atmosphere, carrying out heating in 750 ℃ * 2 hours, to implement 25 circulations as 1 round-robin corrosion test with the operation that is cooled to room temperature, remove behind the corrosion product of test film surface generation with ammonium citrate (ammonium citrate) aqueous solution, measure the reduction (depth of corrosion) of thickness of slab, and high temperature resistant salt damage corrodibility is estimated.
Fatique testing at elevated temperature
Use Shen Keshi (Schenck type) high temperature fatigue testing machine, under 750 ℃, the condition of 22Hz, make the stress in bending (bending stress) that is applied on the test film various variations take place and carry out full alternation fatique testing at elevated temperature (completely-reversed high-temperaturefatigue test).And, obtain stress in bending that 1,000,000 bendings also can not rupture as safe range of stress.
Melt out the basal component with C:0.01 quality %-Si:0.31 quality %-Mn:0.34 quality %-P:0.03 quality %-S:0.005 quality %-Cr:16 quality %-Al:0.018 quality %-N:0.01 quality %-Nb:0.47 quality %-B:0.0006 quality % forms and make the steel that Mo content changes and make steel ingot in the scope of 0.65～2.41 quality % after in the laboratory mode, with with experiment 2 identical conditions, making thickness of slab is the cold rolled annealed plate of 0.4mm, supplies in high temperature salt damage corrosion test and fatique testing at elevated temperature.
Fig. 2 is used to represent the influence of Nb content to high temperature salt damage corrosive property and the generation of high temperature fatigue characteristic.From this Fig. 2 as can be known, by containing the Nb more than the 0.3 quality %, can obtain the steel plate of high temperature resistant salt damage corrodibility and high temperature fatigue characteristic good.And Fig. 3 is used to represent the influence of Mo content to high temperature salt damage corrosive property and the generation of high temperature fatigue characteristic, by containing the Mo more than the 1.25 quality %, can obtain the steel plate of high temperature resistant salt damage corrodibility and high temperature fatigue characteristic good as can be known.
By make the B content that uses in experiment 1 is that the final annealing temperature of the cold-reduced sheet of 8 quality ppm (0.0008 quality %) changes in 990 ℃～1070 ℃ scope, and the average crystallite particle diameter of cold rolled annealed plate is changed in the scope of 19～73 μ m.And, from described cold rolled annealed plate, choose and test the tension test sheet (parallel portion width: 150mm, parallel portion length 25mm) of 1 identical special shape abreast with rolling direction, for measuring uniform elongation in tension test.
The said determination result as shown in Figure 4.From this Fig. 4 as can be known, the average crystallite particle diameter of steel plate increases as the uniform elongation of the index of corrugated tube processibility when 35 μ m are following.Think that average crystallite particle diameter uniform elongation cause of increased when 35 μ m are following is, because the crystal grain miniaturization, the strain when making distortion thereby the number of the crystal grain in the thickness of slab direction of section of steel plate increases is carried out equably.
B content to manufacturing in experiment 1 is the surfaceness of the cold rolled annealed plate of 8 quality ppm (0.0008 quality %), by the surfaceness (counting the scope of 0.07～0.80 μ m with arithmetic average roughness Ra) of change cold roll, and it is changed in the scope of counting 0.1～1.08 μ m with arithmetic average roughness Ra.And, from described cold rolled annealed plate, choose and test the tension test sheet (parallel portion width: 150mm, parallel portion length 25mm) of 1 identical special shape abreast with rolling direction, for measuring uniform elongation in tension test.
The said determination result as shown in Figure 5.From the result of this Fig. 5 as can be known, steel surface roughness, increases as the uniform elongation of the index of corrugated tube processibility when 0.4 μ m is following in arithmetic average roughness Ra.Think that its reason is, Ra surpasses 0.4 μ m and under the more coarse situation, because the concavo-convex starting point that becomes crackle in the tension test on surface, thereby causes the reduction of uniform elongation.
The present invention is that the result according to above-mentioned test 1 to 5 develops.
Then the one-tenth of ferrite stainless steel sheet of the present invention is grouped into and describes.
Below the C:0.015 quality %
C is the element that the ductility that makes steel plate, toughness reduce, and particularly owing to also the corrugated tube processibility as emphasis of the present invention is produced detrimentally affect, thereby preferably reduces as far as possible, make C on be limited to 0.015 quality %.And then preferably below 0.010 quality %.In addition in the present invention, even because C content denier can not produce any detrimentally affect yet, thereby needn't stipulate lower limit.
Below the Si:1.0 quality %
Though Si is to improving scale resistance, high temperature resistant salt damage corrodibility effective elements, also is to make the steel hardization, the element that causes ductility to reduce.Particularly, Si surpassed 1.0 quality % and when adding owing to significantly reduce corrugated tube processibility as emphasis of the present invention, thereby make Si on be limited to 1.0 quality %.Though do not limit the lower limit of Si especially,, preferably contain more than the 0.2 quality % from guaranteeing scale resistance, the corrosive viewpoint of high temperature resistant salt damage.And then be preferably 0.3～0.6 quality %.
Below the Mn:1.0 quality %
Mn is the effective elements that the welding and solidifying crack susceptibility in the ferritic stainless steel with excellent formability that adds Nb is reduced.But because Mn is austenite stabilizer element, thereby during heavy addition, the stability of the ferritic phase when making high temperature reduces, and according to circumstances generates the reduction that austenite causes scale resistance mutually.And because Mn makes the steel hardization by solution hardening, when particularly surpassing 1.0 quality %, the reduction of processibility is very remarkable, thereby makes and be limited to 1.0 quality %.In addition, though the lower limit of Mn is not set especially,, preferably contain more than the 0.3 quality % from welding and solidifying crack susceptibility is suppressed to lower viewpoint.And then be preferably 0.4～0.7 quality %.
Below the P:0.04 quality %
P is the element that toughness and ductility are reduced.Particularly, surpass 0.04 quality % and contain sometimes,, thereby make and be limited to 0.04 quality % because the reduction of toughness, ductility becomes significantly.And then preferably below 0.03 quality %.In addition, even also can not produce detrimentally affect, thereby needn't limit lower limit to effect of the present invention because P content is low.
Below the S:0.010 quality %
S is the element that erosion resistance, scale resistance are reduced.Particularly, when surpassing 0.010 quality %,, thereby make and be limited to 0.010 quality % because the reduction of erosion resistance, scale resistance becomes significantly.And then preferably below 0.007 quality %.In addition, even also can not produce detrimentally affect, thereby needn't limit lower limit to effect of the present invention because S content is low.
Cr:11～below the 19 quality %
Cr is the main alloy element that constitutes ferrite stainless steel sheet, is element essential when improving erosion resistance, scale resistance.In order to obtain this effect, Cr need add more than the 11 quality %.On the other hand, during heavy addition Cr, not only cause the hardization of steel, reduce but also make as the corrugated tube processibility of emphasis of the present invention, thus make Cr on be limited to 19 quality %.Be preferably the scope of 13～19 quality %.
Below the N:0.015 quality %
N is the element that toughness, ductility are reduced, and its content is reduced as far as possible.Particularly, owing to also the corrugated tube processibility as emphasis of the present invention is produced detrimentally affect, thereby N is limited to below the 0.015 quality %.And then preferably below 0.010 quality %.In addition, because the N amount more can not produce any detrimentally affect to the characteristic as corrugated tube, thereby do not limit lower value.
Below the Al:0.15 quality %
Al is powerful deoxidant element, adds in order to reduce the oxygen in the steel when the refining.And, still be to the raising effective elements of scale resistance.But, during excessive interpolation Al, cause the reduction of toughness, ductility, when particularly surpassing 0.15 quality %,, thereby be limited to below the 0.15 quality % because this trend becomes significantly.And then preferably below 0.07 quality %.In addition, though do not limit lower limit especially, the deoxidation when fully carrying out refining is preferably added more than the 0.003 quality %.
Nb:0.3～0.7 quality %, Mo:1.25～2.5 quality %
Mo and Nb are the elements that improves hot properties, are important interpolation element in the present invention.As can be known, when containing the Nb more than the 0.3 quality %, has the effect of improving high temperature resistant salt damage corrodibility and high temperature fatigue characteristic from above-mentioned experiment 2.But when Nb content surpassed 0.7 quality %, it is remarkable that the reduction of toughness, ductility becomes.Thus, make Nb content in the scope of 0.3～0.7 quality %.And then be preferably 0.4～0.55 quality %.
And,, when containing the Mo more than the 1.25 quality %, have the effect of improving high temperature resistant salt damage corrodibility and high temperature fatigue characteristic as can be known from above-mentioned experiment 3.But, under the situation about containing, cause ductility, flexible to reduce making Mo surpass 2.5 quality %.Thus, make Mo content in the scope of 1.25～2.5 quality %.And then be preferably 1.35～2.25 quality %.
B:0.0003～0.003 quality %
B is the important element that brings the raising of corrugated tube processibility, is essential element in the present invention.From the result (Fig. 1) of above-mentioned experiment 1 as can be known, improve uniform elongation, can obtain good corrugated tube processibility by the B that contains 0.0003 quality %.On the other hand, under the situation about containing, cause the reduction of uniform elongation on the contrary making B ultrasonic cross 0.003 quality %.Thus, in the present invention, the content that makes B is in the scope of 0.0003～0.003 quality %.And then be preferably 0.0005～0.0020 quality %.
In addition, ferrite stainless steel sheet of the present invention, except above-mentioned essential composition, characteristic is added following composition as requested.
Be selected among Cu:0.1～0.6 quality %, Ni:0.1～0.6 quality % and Co:0.03～0.6 quality % more than a kind or 2 kinds
Cu, Ni and Co are the effective elements of improving to toughness and erosion resistance.In order to obtain described effect, preferred add be selected from that Cu:0.1 quality % is above, Ni:0.1 quality % is above and Co:0.03 quality % in above more than a kind or 2 kinds.But because excessive interpolation makes the steel hardization, thereby its upper limit is preferably Cu:0.6 quality %, Ni:0.6 quality %, Co:0.6 quality % respectively.And then preferred range is Cu:0.20～0.50 quality %, Ni:0.20～0.50 quality % and Co:0.04～0.40 quality %.
Be selected among V:0.04～1.0 quality %, W:0.04～5.0 quality %, Ta:0.04～1.0 quality % and Ti:0.02～1.0 quality % more than a kind or 2 kinds
In the steel plate of heavy addition Nb as ferrite stainless steel sheet of the present invention, by interpolation be selected among V, W, Ta and the Ti more than a kind or 2 kinds, the carbonitride of generation disperses imperceptibly and makes the crystal grain miniaturization, thereby improves toughness.And, the time exist under the situation of pollution (Contamination) of C, N in welding, owing to its carbonitride as V etc. being fixed, suppress the generation of Cr carbonitride and can prevent that Cr lacks the formation of layer, thereby also the raising of the erosion resistance of weld part is made contributions.In order to obtain described effect, V preferably adds more than the 0.04 quality %, W preferably adds more than the 0.04 quality %, Ta preferably adds more than the 0.04 quality %, Ti preferably adds more than the 0.02 quality %.But, exceedingly during heavy addition, the toughness of steel plate itself is reduced and reduces manufacturability, thereby its upper limit is preferably V:1.0 quality %, W:5.0 quality %, Ta:1.0 quality % and Ti:1.0 quality % respectively.And then preferred range is V:0.06～0.5 quality %, W:0.1～3.5 quality %, Ta:0.1～0.5 quality % and Ti:0.05～0.5 quality %.
Then, the manufacture method that is fit to this invention steel describes.Creating conditions of this invention steel do not limit especially, can utilize the common manufacture method of ferritic stainless steel with excellent formability.
For example, will be adjusted into the molten steel of above-mentioned suitable compositing range, utilize smelting furnaces such as converter, electric furnace or refinings such as ladle refining, vacuum refinement to carry out melting after, by continuous metal cast process or make and carry out hot rolling after base one cogging method is made steel billet.Can also carry out hot-rolled sheet annealing, pickling as required.And, successively via cold rolling, final annealing, each operation of pickling and make cold rolled annealed plate.And, can also particularly carry out skin-pass as required for the surface roughness Ra of adjusting steel plate.
In the further preferred manufacture method, with a part of condition of hot-rolled process and cold rolling process as specified conditions.When making steel, preferably, contain the molten steel that above-mentioned essential composition reaches the composition that adds as required, and carry out secondary refining by the VOD method by meltings such as converter or electric furnaces.The molten steel that melts out can be made the former material of steel by known manufacture method, still according to the viewpoint of productivity and quality, preferably adopts continuous metal cast process.The former material of the steel that continuous casting obtains for example is heated to 1000～1250 ℃, makes the hot-rolled sheet of regulation thickness of slab by hot rolling.This hot-rolled sheet, as required, implement the continuous annealing of 600～800 ℃ batch annealing or 900 ℃～1100 ℃ after, become the hot-rolled sheet goods of peeling by pickling etc.And, as required, also can before pickling, carry out shot peening and remove peeling.
And, become cold-reduced sheet through behind the cold rolling process by the hot-roll annealing plate that obtains with upper type.In this cold rolling process,, also can comprise cold rolling more than 2 times of process annealing as required according to the condition of production.Total reduction by the cold rolling cold rolling process that constitutes more than 1 time or 2 times is more than 60%, and is preferred more than 70%.Cold-reduced sheet carries out 950～1150 ℃ and then be preferably 980～1120 ℃ continuous annealing (final annealing), makes cold rolled annealed plate after then implementing pickling.And, can also particularly,, can also carry out shape, the quality adjustment of steel plate as required except after cold rolled annealed after-applied slight rolling (skin-pass etc.) in order to adjust the surface roughness Ra of steel plate.
Use the cold rolled annealed plate of making like this and obtaining, implement bending machining, make the bellows stock pipe by common arc welding method (arc welding process) or laser welding (Laser welding) such as TIG (Tungsten Inert Gas), plasma body welding (plasma welding).Resulting bellows stock pipe by the hydroforming method, is made the corrugated tube of regulation crest portion external diameter.
In addition, the steel plate of the preferred thickness of slab of ferrite stainless steel sheet of the present invention below 0.5mm.As mentioned above, corrugated tube forms the accordion-like of parallel wave type, has the function that absorbs thermal expansion, vibrates the displacement that causes.Above-mentioned displacement, as bending and applying load, at this moment, material strain became big when thickness of slab was big on corrugated tube.And the strain that surpasses elastic limit of materials becomes plastix strain, becomes the reason of fatigue destruction that causes corrugated tube.Therefore, from preventing the viewpoint of fatigure failure, thickness of slab is thin more preferred more.In the present invention, be considered as manufacturability, the manufacturing cost of the stainless steel plate of former material, as the scope that in fact problem does not take place, preferred thickness of slab is below 0.5mm.
And with the bellows stock pipe of ferrite stainless steel sheet of the present invention as former material, preferred outer diameter A is individual layer or the bilayer structure of 28～80mm φ.This be because, the displacement in the elastic limit scope that corrugated tube can absorb is decided by the high H of its tooth, even but the high H of identical tooth, former external diameter of pipe A is thin more, it is big that the pipe expanding rate of tooth portion just becomes, thereby be difficult to be shaped.That is, under the thinner situation of former external diameter of pipe A, the high H of the tooth that can be shaped diminishes.Therefore, in automobile exhaust system corrugated tube purposes, in order to absorb the displacement of regulation, its former external diameter of pipe A is preferably more than 28mm φ.On the other hand, under the situation of, thin-walled big, because the rigidity deficiency of corrugated tube itself, thereby be easy to generate conquassation, buckle, in fact be difficult to use at former external diameter of pipe A.Therefore, former external diameter of pipe A is preferably below 80mm φ.
In addition, need in design under the inflexible situation of corrugated tube, considered increase wall thickness t (thickness of slab t), but as mentioned above, because the increase of wall thickness t becomes reason of fatigue destruction, thus not preferred.For fear of this situation, can form multiple pipe and guarantee rigidity, intensity by the steel plate that makes thin-walled is overlapping.Specifically, preferably make double wall tube, make triple tube when above, not preferred aspect manufacturability, manufacturing cost.And if wall thickness is identical, when making double wall tube, because rigidity reduces, flexibility increases, thereby also has the effect that improves fatigue strength.And according to environment for use, the internal surface at corrugated tube requires characteristic different with outside surface sometimes, in this case, preferably makes and uses the double wall tube that meets each former material that requires.
Embodiment
Embodiment 1
With high frequency vacuum melting stove melt out have various steel that one-tenth is grouped into shown in the table 1 and the steel ingot of making 50kg after, with 1170 ℃ the heating 1 hour after, establishing finishing temperature is 800 ℃ hot rolling, thereby makes the hot-rolled sheet that thickness of slab is 3.5mm.Then, after this hot-rolled sheet being implemented 1040 ℃ * 30 seconds annealing, the oxide skin that forms at surface of steel plate is carried out pickling and removed, and carry out cold rolling and make the cold-reduced sheet that thickness of slab is 0.4mm, after the degreasing, carry out 1030 ℃ * 30 seconds annealing and make cold rolled annealed plate.From this cold rolled annealed plate, choose the tension test sheet (parallel portion width: 150mm, parallel portion length 25mm) of above-mentioned special shape abreast and carry out tension test with rolling direction, and measure uniform elongation.And, also supply each characteristic to be estimated in above-mentioned high temperature salt damage corrosion test and fatique testing at elevated temperature.
Above-mentioned test-results is represented as shown in table 2.As can be known be, be suitable for ferrite stainless steel sheet of the present invention, compare with the steel plate of comparative example, higher as the uniform elongation of corrugated tube processibility index, and high temperature salt damage corrosive property and high temperature fatigue characteristic are also good.
With high frequency vacuum melting stove melt out have various steel that one-tenth is grouped into shown in the table 3 and the steel ingot of making 50kg after, with 1170 ℃ the heating 1 hour after, establishing finishing temperature is 800 ℃ hot rolling, thereby makes the hot-rolled sheet that thickness of slab is 3.5mm.Then, after the hot-rolled sheet that this hot-rolled sheet was implemented 1040 ℃ * 30 seconds is annealed, to carrying out pickling in the oxide skin of surface of steel plate formation and removing, and carry out cold rolling and make the cold-reduced sheet that thickness of slab is 0.4mm, after the degreasing, carry out 30 seconds annealing and the average crystallite particle diameter D of steel plate is changed with 990～1050 ℃ temperature, the average crystallite particle diameter of cold rolled annealed plate is changed.
From this cold rolled annealed plate, choose the tension test sheet (parallel portion width: 150mm, parallel portion length 25mm) of above-mentioned special shape abreast and carry out tension test with rolling direction, and measure uniform elongation.And the average crystallite particle diameter grinds, after the etching, uses observation by light microscope 0.5mm the section parallel with rolling direction (with the vertical section of plate face) of steel plate
2Above area is measured the crystal grain number in the visual field, obtains the average area of each crystal grain by this crystal grain number and field of view area, calculates according to this value and justifies suitable diameter, should be worth as the average crystallite particle diameter.And, also supply each characteristic to be estimated in above-mentioned high temperature salt damage corrosion test and fatique testing at elevated temperature.
Above-mentioned test-results is as shown in table 4.As can be known be, be suitable for ferrite stainless steel sheet of the present invention, compare with the steel plate of comparative example, higher as the uniform elongation of corrugated tube processibility index, and high temperature salt damage corrosive property and high temperature fatigue characteristic are also good.And as can be known be, the steel plate of the present invention of table 3 and table 4 (steel No.1～6) is compared with the table 1 of embodiment 1 and the steel plate of the present invention of table 2 (steel No.1～6), because the average crystallite particle diameter D that makes steel plate is below 35 μ m, thereby further improve uniform elongation.
With high frequency vacuum melting stove melt out have various steel that one-tenth is grouped into shown in the table 5 and the steel ingot of making 50kg after, with 1170 ℃ the heating 1 hour after, establishing finishing temperature is 800 ℃ hot rolling, thereby makes the hot-rolled sheet that thickness of slab is 3.5mm.Then, after this hot-rolled sheet being implemented 1040 ℃ * 30 seconds annealing, the oxide skin that forms at surface of steel plate is carried out pickling and removed, and carry out cold rolling and make the cold-reduced sheet that thickness of slab is 0.4mm, after the degreasing, carry out 1030 ℃ * 30 seconds annealing and make cold rolled annealed plate.At this moment, the roughness (counting the scope of 0.07～0.80 μ m with arithmetic average roughness Ra) of the working roll by changing when cold rolling changes the surfaceness of steel plate.From this cold rolled annealed plate, choose the tension test sheet (parallel portion width: 150mm, parallel portion length 25mm) of above-mentioned special shape abreast and carry out tension test with rolling direction, and measure uniform elongation.And, also supply each characteristic to be estimated in above-mentioned high temperature salt damage corrosion test and fatique testing at elevated temperature.And the surfaceness of steel plate is used the contact pin type surface roughness measurement device according to JIS B0651, according to JIS B0601 (version in 1997), and the arithmetic average roughness Ra of the rectangular direction of rolling direction of mensuration and steel plate.
Above-mentioned test-results is as shown in table 6.As can be known be, be suitable for ferrite stainless steel sheet of the present invention, compare with the steel plate of comparative example, higher as the uniform elongation of corrugated tube processibility index, and high temperature salt damage corrosive property and high temperature fatigue characteristic are also good.And as can be known be, the steel plate of the present invention of table 5 and table 6 (steel No.1～6) is compared with the table 1 of embodiment 1 and the steel plate of the present invention of table 2 (steel No.1～6), because the surface roughness Ra that makes steel plate is below 0.40 μ m, thereby further improve uniform elongation.
The stainless cold rolled annealed steel plate that use is used in the steel No.1 of the table 5 of the steel No.1 of the table 3 of steel No.1, the embodiment 2 of the table 1 of embodiment 1 and embodiment 3, implement bending machining, making external diameter by the TIG welding process is the bellows stock pipe of 50mm, by the hydroforming method, do not make the tooth height is the corrugated tube of 13mm with cracking to resulting bellows stock pipe.
Utilize possibility on the industry
Ferrite stainless steel sheet of the present invention can also be used for heat exchanger, fuel cell The field headed by the purposes that requires hot properties, field in.
Table 1
| Steel No. | Chemical composition (quality %) | Remarks | |||||||||||
| C | Si | Mn | P | S | Cr | N | Al | Mo | Nb | B | Other | ||
| 1 | 0.005 | 0.29 | 0.77 | 0.031 | 0.004 | 15.2 | 0.006 | 0.004 | 1.66 | 0.49 | 0.0005 | - | Example |
| 2 | 0.006 | 0.3a | 0.94 | 0.028 | 0.003 | 18.8 | 0.008 | 0.011 | 2.03 | 0.56 | 0.0011 | - | Example |
| 3 | 0.009 | 0.88 | 0.36 | 0.033 | 0.005 | 13.4 | 0.007 | 0.041 | 1.86 | 0.49 | 0.0004 | - | Example |
| 4 | 0.006 | 0.27 | 0.36 | 0.028 | 0.001 | 14.9 | 0.008 | 0.022 | 1.46 | 0.51 | 0.0006 | Co：0.051，Ni：0.21 | Example |
| 5 | 0.004 | 0.55 | 0.79 | 0.034 | 0.006 | 14.1 | 0.009 | 0.008 | 1.29 | 0.34 | 0.0007 | Ti：0.11，V：0.061，Cu：0.21 | Example |
| 6 | 0.011 | 0.28 | 0.34 | 0.022 | 0.004 | 17.2 | 0.007 | 0.078 | 1.47 | 0.62 | 0.0018 | W：0.31，Ta：0.11 | Example |
| 7 | 0.006 | 0.31 | 0.68 | 0.030 | 0.003 | 15.1 | 0.007 | 0.011 | 1.61 | 0.52 | 0.0001 | - | Comparative example |
| 8 | 0.005 | 0.27 | 0.71 | 0.028 | 0.004 | 15.3 | 0.005 | 0.018 | 1.60 | 0.24 | 0.0006 | - | Comparative example |
| 9 | 0.006 | 0.31 | 0.74 | 0.033 | 0.001 | 15.2 | 0.006 | 0.008 | 0.77 | 0.52 | 0.0007 | - | Comparative example |
| 10 | 0.004 | 0.06 | 0.38 | 0.021 | 0.001 | 14.8 | 0.006 | 0.035 | 1.81 | 0.49 | 0.0005 | W：3.01 | Example |
| 11 | 0.005 | 0.21 | 0.04 | 0.020 | 0.001 | 16.1 | 0.006 | 0.024 | 1.70 | 0.40 | 0.0006 | Ti：0.60 | Example |
| 12 | 0.006 | 0.33 | 0.15 | 0.024 | 0.003 | 13.8 | 0.005 | 0.005 | 1.52 | 0.51 | 0.0008 | Ta：0.63 | Example |
| 13 | 0.007 | 0.24 | 0.18 | 0.018 | 0.001 | 14.2 | 0.005 | 0.008 | 1.59 | 0.42 | 0.0011 | V：0.70 | Example |
Table 2
| Steel No. | Result of the test | Remarks | ||
| Uniform elongation (%) | High temperature salt damage corrosion depth (mm) | The fatigue at high temperature limit (MPa) | ||
| 1 | 15.1 | ＜0.1 | 123 | Example |
| 2 | 15.3 | ＜0.1 | 121 | Example |
| 3 | 15.2 | ＜0.1 | 124 | Example |
| 4 | 15.2 | ＜0.1 | 124 | Example |
| 5 | 15.1 | ＜0.1 | 123 | Example |
| 6 | 15.3 | ＜0.1 | 124 | Example |
| 7 | 13.9 | ＜0.1 | 123 | Comparative example |
| 8 | 15.1 | 0.13 | 88 | Comparative example |
| 9 | 15.2 | 0.15 | 94 | Comparative example |
| 10 | 15.2 | ＜0.1 | 127 | Example |
| 11 | 15.1 | ＜0.1 | 122 | Example |
| 12 | 15.3 | ＜0.1 | 123 | Example |
| 13 | 15.2 | ＜0.1 | 123 | Example |
Table 3
| Steel No. | Chemical composition (quality %) | Average crystallite particle diameter (μ m) | Remarks | |||||||||||
| C | Si | Mn | P | S | Cr | N | Al | Mo | Nb | B | Other | |||
| 1 | 0.005 | 0.29 | 0.77 | 0.031 | 0.004 | 15.2 | 0.006 | 0.004 | 1.66 | 0.49 | 0.0005 | - | 29 | Example |
| 2 | 0.006 | 0.33 | 0.94 | 0.028 | 0.003 | 18.8 | 0.008 | 0.011 | 2.03 | 0.56 | 0.0011 | - | 31 | Example |
| 3 | 0.009 | 0.88 | 0.36 | 0.033 | 0.005 | 13.4 | 0.007 | 0.041 | 1.86 | 0.49 | 0.0004 | - | 19 | Example |
| 4 | 0.006 | 0.27 | 0.36 | 0.028 | 0.001 | 14.9 | 0.008 | 0.022 | 1.46 | 0.51 | 0.0006 | Co：0.051，Ni：0.21 | 25 | Example |
| 5 | 0.004 | 0.55 | 0.79 | 0.034 | 0.006 | 14.1 | 0.009 | 0.008 | 1.29 | 0.34 | 0.0007 | Ti：0.11，V：0.061，Cu：0.21 | 26 | Example |
| 6 | 0.011 | 0.28 | 0.34 | 0.022 | 0.004 | 17.2 | 0.007 | 0.078 | 1.47 | 0.62 | 0.0018 | W：0.31，Ta：0.11 | 23 | Example |
| 7 | 0.006 | 0.31 | 0.68 | 0.030 | 0.003 | 15.1 | 0.007 | 0.011 | 1.61 | 0.52 | 0.0001 | - | 21 | Comparative example |
| 8 | 0.005 | 0.27 | 0.71 | 0.028 | 0.004 | 15.3 | 0.005 | 0.018 | 1.60 | 0.24 | 0.0006 | - | 28 | Comparative example |
| 9 | 0.006 | 0.31 | 0.74 | 0.033 | 0.001 | 15.2 | 0.006 | 0.008 | 0.77 | 0.52 | 0.0007 | - | 33 | Comparative example |
| 10 | 0.006 | 0.33 | 0.94 | 0.028 | 0.003 | 18.8 | 0.008 | 0.011 | 2.03 | 0.56 | 0.0011 | - | 66 | Comparative example |
| 11 | 0.007 | 0.06 | 0.31 | 0.021 | 0.001 | 16.2 | 0.006 | 0.045 | 1.86 | 0.43 | 0.0007 | Ti：0.73 | 28 | Example |
| 12 | 0.004 | 0.21 | 0.48 | 0.020 | 0.002 | 14.6 | 0.006 | 0.033 | 1.70 | 0.49 | 0.0006 | W：2.91 | 25 | Example |
| 13 | 0.006 | 0.30 | 0.07 | 0.024 | 0.003 | 16.2 | 0.008 | 0.004 | 1.53 | 0.48 | 0.0011 | Ta：0.89 | 27 | Example |
| 14 | 0.007 | 0.22 | 0.18 | 0.018 | 0.002 | 15.3 | 0.004 | 0.021 | 1.61 | 0.40 | 0.0005 | V：0.59 | 30 | Example |
Table 4
| Steel No. | Result of the test | Remarks | ||
| Uniform elongation (%) | High temperature salt damage corrosion depth (mm) | The fatigue at high temperature limit (MPa) | ||
| 1 | 16.4 | ＜0.1 | 123 | Example |
| 2 | 16.5 | ＜0.1 | 121 | Example |
| 3 | 16.7 | ＜0.1 | 124 | Example |
| 4 | 16.7 | ＜0.1 | 124 | Example |
| 5 | 16.6 | ＜0.1 | 123 | Example |
| 6 | 16.7 | ＜0.1 | 124 | Example |
| 7 | 14.6 | ＜0.1 | 123 | Comparative example |
| 8 | 16.6 | 0.13 | 88 | Comparative example |
| 9 | 16.4 | 0.15 | 94 | Comparative example |
| 10 | 15.2 | ＜0.1 | 122 | Comparative example |
| 11 | 16.2 | ＜0.1 | 122 | Example |
| 12 | 16.5 | ＜0.1 | 128 | Example |
| 13 | 16.3 | ＜0.1 | 124 | Example |
| 14 | 16.2 | ＜0.1 | 123 | Example |
Table 5
| Steel No. | Chemical composition (quality %) | Ra (μm) | Remarks | |||||||||||
| C | Si | Mn | P | S | Cr | N | Al | Mo | Nb | B | Other | |||
| 1 | 0.005 | 0.29 | 0.77 | 0.031 | 0.004 | 15.2 | 0.006 | 0.004 | 1.66 | 0.49 | 0.0005 | - | 0.24 | Example |
| 2 | 0.006 | 0.33 | 0.94 | 0.028 | 0.003 | 18.8 | 0.008 | 0.011 | 2.03 | 0.56 | 0.0011 | - | 0.23 | Example |
| 3 | 0.009 | 0.88 | 0.36 | 0.033 | 0.005 | 13.4 | 0.007 | 0.041 | 1.86 | 0.49 | 0.0004 | - | 0.36 | Example |
| 4 | 0.006 | 0.27 | 0.36 | 0.028 | 0.001 | 14.9 | 0.008 | 0.022 | 1.46 | 0.51 | 0.0006 | Co：0.051，Ni：0.21 | 0.17 | Example |
| 5 | 0.004 | 0.55 | 0.79 | 0.034 | 0.006 | 14.1 | 0.009 | 0.008 | 1.29 | 0.34 | 0.0007 | Ti：0.11，V：0.061，Cu：0.21 | 0.22 | Example |
| 6 | 0.011 | 0.28 | 0.34 | 0.022 | 0.004 | 17.2 | 0.007 | 0.078 | 1.47 | 0.62 | 0.0018 | W：0.31，Ta：0.11 | 0.37 | Example |
| 7 | 0.006 | 0.31 | 0.68 | 0.030 | 0.003 | 15.1 | 0.007 | 0.011 | 1.61 | 0.52 | 0.0001 | - | 0.23 | Comparative example |
| 8 | 0.005 | 0.27 | 0.71 | 0.028 | 0.004 | 15.3 | 0.005 | 0.018 | 1.60 | 0.24 | 0.0006 | - | 0.24 | Comparative example |
| 9 | 0.006 | 0.31 | 0.74 | 0.033 | 0.001 | 15.2 | 0.006 | 0.008 | 0.77 | 0.52 | 0.0007 | - | 0.23 | Comparative example |
| 10 | 0.006 | 0.33 | 0.94 | 0.028 | 0.003 | 18.8 | 0.008 | 0.011 | 2.03 | 0.56 | 0.0011 | - | 0.51 | Comparative example |
| 11 | 0.005 | 0.10 | 0.52 | 0.022 | 0.002 | 15.6 | 0.007 | 0.025 | 1.78 | 0.49 | 0.0004 | W：3.06 | 0.24 | Example |
| 12 | 0.006 | 0.22 | 0.09 | 0.018 | 0.001 | 14.7 | 0.006 | 0.029 | 1.54 | 0.50 | 0.0006 | Ti：0.72 | 0.14 | Example |
| 13 | 0.005 | 0.09 | 0.40 | 0.023 | 0.004 | 16.7 | 0.006 | 0.004 | 1.44 | 0.47 | 0.0006 | Ta：0.81 | 0.22 | Example |
| 14 | 0.004 | 0.21 | 0.18 | 0.024 | 0.001 | 14.0 | 0.004 | 0.009 | 1.68 | 0.48 | 0.0011 | V：0.69 | 0.18 | Example |
Table 6
| Steel No. | Result of the test | Remarks | ||
| Uniform elongation (%) | High temperature salt damage corrosion depth (mm) | The fatigue at high temperature limit (MPa) | ||
| 1 | 16.6 | ＜0.1 | 123 | Example |
| 2 | 16.7 | ＜0.1 | 121 | Example |
| 3 | 16.4 | ＜0.1 | 124 | Example |
| 4 | 16.7 | ＜0.1 | 124 | Example |
| 5 | 16.4 | ＜0.1 | 123 | Example |
| 6 | 16.7 | ＜0.1 | 124 | Example |
| 7 | 14.5 | ＜0.1 | 123 | Comparative example |
| 8 | 16.4 | 0.13 | 88 | Comparative example |
| 9 | 16.3 | 0.15 | 94 | Comparative example |
| 10 | 15.1 | ＜0.1 | 122 | Comparative example |
| 11 | 16.2 | ＜0.1 | 129 | Example |
| 12 | 16.1 | ＜0.1 | 125 | Example |
| 13 | 16.2 | ＜0.1 | 124 | Example |
| 14 | 16.3 | ＜0.1 | 124 | Example |
Claims (14)
1. ferrite stainless steel sheet for bellows stock pipe, wherein, contain that C:0.015 quality % is following, Si:1.0 quality % following, Mn:1.0 quality % is following, P:0.04 quality % is following, S:0.010 quality % is following, Cr:11～19 quality %, N:0.015 quality % are following, Al:0.15 quality % is following, Mo:1.25～2.5 quality %, Nb:0.3～0.7 quality %, B:0.0003～0.003 quality %, surplus is made of Fe and unavoidable impurities.
2. ferrite stainless steel sheet for bellows stock pipe according to claim 1, wherein, except described one-tenth is grouped into, also contains and be selected among Cu:0.1～0.6 quality %, Ni:0.1～0.6 quality % and the Co:0.03～0.6 quality % more than a kind or 2 kinds.
3. ferrite stainless steel sheet for bellows stock pipe according to claim 1 and 2, wherein, except described one-tenth is grouped into, also contains and be selected among V:0.04～1.0 quality %, W:0.04～5.0 quality %, Ta:0.04～1.0 quality % and the Ti:0.02～1.0 quality % more than a kind or 2 kinds.
4. according to each described ferrite stainless steel sheet for bellows stock pipe in the claim 1 to 3, be used for thickness of slab below 0.5mm, external diameter is the individual layer of 28～80mm φ or the former pipe of double-deck automobile exhaust system corrugated tube.
5. according to each described ferrite stainless steel sheet for bellows stock pipe in the claim 1 to 4, wherein, the average crystallite particle diameter is below 35 μ m.
6. according to each described ferrite stainless steel sheet for bellows stock pipe in the claim 1 to 4, wherein, surface roughness Ra is below 0.4 μ m.
7. ferrite stainless steel sheet for bellows stock pipe, wherein, contain that C:0.015 quality % is following, Si:1.0 quality % following, Mn:1.0 quality % is following, P:0.04 quality % is following, S:0.010 quality % is following, Cr:11～19 quality %, N:0.015 quality % are following, Al:0.15 quality % is following, Mo:1.25～2.5 quality %, Nb:0.3～0.7 quality %, B:0.0003～0.003 quality %, surplus is made of Fe and unavoidable impurities, and the average crystallite particle diameter is below 35 μ m.
8. ferrite stainless steel sheet for bellows stock pipe according to claim 7, wherein, except described one-tenth is grouped into, also contains and be selected among Cu:0.1～0.6 quality %, Ni:0.1～0.6 quality % and the Co:0.03～0.6 quality % more than a kind or 2 kinds.
9. according to claim 7 or 8 described ferrite stainless steel sheet for bellows stock pipe, wherein, except described one-tenth is grouped into, also contains and be selected among V:0.04～1.0 quality %, W:0.04～5.0 quality %, Ta:0.04～1.0 quality % and the Ti:0.02～1.0 quality % more than a kind or 2 kinds.
10. according to each described ferrite stainless steel sheet for bellows stock pipe in the claim 7 to 9, be used for thickness of slab below 0.5mm, external diameter is the individual layer of 28～80mm φ or the former pipe of double-deck automobile exhaust system corrugated tube.
11. ferrite stainless steel sheet for bellows stock pipe, wherein, contain that C:0.015 quality % is following, Si:1.0 quality % following, Mn:1.0 quality % is following, P:0.04 quality % is following, S:0.010 quality % is following, Cr:11～19 quality %, N:0.015 quality % are following, Al:0.15 quality % is following, Mo:1.25～2.5 quality %, Nb:0.3～0.7 quality %, B:0.0003～0.003 quality %, surplus is made of Fe and unavoidable impurities, and surface roughness Ra is below 0.4 μ m.
12. ferrite stainless steel sheet for bellows stock pipe according to claim 11, wherein, except described one-tenth is grouped into, also contains and be selected among Cu:0.1～0.6 quality %, Ni:0.1～0.6 quality % and the Co:0.03～0.6 quality % more than a kind or 2 kinds.
13. according to claim 11 or 12 described ferrite stainless steel sheet for bellows stock pipe, wherein, except described one-tenth is grouped into, also contains and be selected among V:0.04～1.0 quality %, W:0.04～5.0 quality %, Ta:0.04～1.0 quality % and the Ti:0.02～1.0 quality % more than a kind or 2 kinds.
14. according to each described ferrite stainless steel sheet for bellows stock pipe in the claim 11 to 13, be used for thickness of slab below 0.5mm, external diameter is the individual layer of 28～80mm φ or the former pipe of double-deck automobile exhaust system corrugated tube.
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP169520/2005 | 2005-06-09 | ||
| JP169522/2005 | 2005-06-09 | ||
| JP169521/2005 | 2005-06-09 | ||
| JP2005169521 | 2005-06-09 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN101171353A true CN101171353A (en) | 2008-04-30 |
Family
ID=39391363
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNA2006800148642A Pending CN101171353A (en) | 2005-06-09 | 2006-05-29 | Ferritic stainless steel sheet for original pipe of bellows |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN101171353A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107461297A (en) * | 2017-10-16 | 2017-12-12 | 派腾奥普科技服务（北京）有限公司 | A kind of tidal power generating device |
| CN110462079A (en) * | 2017-03-30 | 2019-11-15 | 杰富意钢铁株式会社 | Ferrite-group stainless steel |
| CN113462973A (en) * | 2021-06-23 | 2021-10-01 | 上汽通用汽车有限公司 | Stainless steel material for automobile exhaust system and automobile exhaust system |
-
2006
- 2006-05-29 CN CNA2006800148642A patent/CN101171353A/en active Pending
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110462079A (en) * | 2017-03-30 | 2019-11-15 | 杰富意钢铁株式会社 | Ferrite-group stainless steel |
| US11560604B2 (en) | 2017-03-30 | 2023-01-24 | Jfe Steel Corporation | Ferritic stainless steel |
| CN107461297A (en) * | 2017-10-16 | 2017-12-12 | 派腾奥普科技服务（北京）有限公司 | A kind of tidal power generating device |
| CN113462973A (en) * | 2021-06-23 | 2021-10-01 | 上汽通用汽车有限公司 | Stainless steel material for automobile exhaust system and automobile exhaust system |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| KR101321681B1 (en) | Hollow member and method for manufacturing same | |
| US7819991B2 (en) | Ferritic stainless steel sheet for raw material pipe for bellows pipe | |
| CN102471841B (en) | The ferrite-group stainless steel of excellent heat resistance | |
| KR20010062057A (en) | Ferritic stainless steel plate having excellent ridging resistance and formability and menufacturing method thereof | |
| EP1889936B1 (en) | Ferrite stainless steel sheet for bellows stock pipe | |
| KR0165152B1 (en) | Ferritic stainless steel for bellows forming | |
| EP2500444A1 (en) | Duplex stainless steel having excellent alkali resistance | |
| JP3551892B2 (en) | Heat resistant ferritic stainless steel and its steel plate | |
| CN101171353A (en) | Ferritic stainless steel sheet for original pipe of bellows | |
| JP4752621B2 (en) | Ferritic stainless steel sheet for bellows tube | |
| CN113166831B (en) | Ferritic stainless steel sheet and method for producing same | |
| JP4752572B2 (en) | Ferritic stainless steel sheet for bellows tube and bellows tube | |
| JP4907079B2 (en) | Ferritic stainless steel welded pipe with excellent pipe workability and ferritic stainless steel sheet for welded pipe | |
| JP2001355049A (en) | Martensitic stainless steel sheet and method for producing the same | |
| JP4752573B2 (en) | Ferritic stainless steel sheet for bellows tube and bellows tube | |
| JP4752571B2 (en) | Ferritic stainless steel sheet for bellows tube and bellows tube | |
| JP2022126000A (en) | Ferritic stainless steel sheet, method for producing the same, and part | |
| JP5093984B2 (en) | Ferritic stainless steel welded pipe excellent in pipe expansion workability and manufacturing method thereof | |
| JP5414769B2 (en) | Ferritic stainless steel welded pipe excellent in pipe expansion workability and manufacturing method thereof | |
| EP3604588B1 (en) | Ferritic stainless steel | |
| US7754344B2 (en) | Ferritic stainless steel welded pipe superior in expandability | |
| CN112888802A (en) | Ferritic stainless steel hot-rolled annealed steel sheet and method for producing same | |
| CN101171352A (en) | Ferrite stainless steel sheet for bellows stock pipe | |
| KR20210062721A (en) | Ferritic stainless steel | |
| JP3844662B2 (en) | Martensitic stainless steel sheet and manufacturing method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C12 | Rejection of a patent application after its publication | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20080430 |