CN101139682A - Straight joint resistance welding oil annular tube steel and manufacturing method thereof - Google Patents
Straight joint resistance welding oil annular tube steel and manufacturing method thereof Download PDFInfo
- Publication number
- CN101139682A CN101139682A CNA2007100536555A CN200710053655A CN101139682A CN 101139682 A CN101139682 A CN 101139682A CN A2007100536555 A CNA2007100536555 A CN A2007100536555A CN 200710053655 A CN200710053655 A CN 200710053655A CN 101139682 A CN101139682 A CN 101139682A
- Authority
- CN
- China
- Prior art keywords
- steel
- per cent
- resistance welding
- annular tube
- straight joint
- 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
Landscapes
- Heat Treatment Of Steel (AREA)
Abstract
The invention provides a steel for straight-seam resistance welding petroleum cannula and its manufacturing method. The chemical components (smelting analysis) of the steel based on the weight percentage are that: C of 0.04 to 0.20 per cent, Si of 0.10 to 0.40 per cent, Mn of 1.20 to 2.00 per cent, Nb of 0.03 to 0.07 per cent, Mo of 0.10 to 0.40 per cent, Cu of 0 to 0.30 per cent, Ni of 0 to 0.40 per cent, B of 0.0005 to 0.0030 per cent, Als of 0.010 to 0.050 per cent, Ti of no more than 0.030 per cent, P of more than 0 but no more than 0.025 per cent, S of more than 0 but no more than 0.005 per cent, and the remainder are iron and unavoidable foreign matters. The actual manufacturing method relates to the controlling of steel making and rolling and cold controlling. The steel of the invention has good impact toughness and weldability, good dimensional controllability of steel stripes, and the thickness error for the same roll of steel can be controlled within plus/minus 40 micrometer. The invention is worthy to be popularized.
Description
Technical field
The present invention relates to a kind of oil casing pipe steel and manufacture method thereof.
Background technology
For a long time, people use weldless steel tube to make petroleum casing pipe always.But there are many weak points in weldless steel tube, and is not good enough as dimensional precision, can produce the spirrillum damage to steel pipe when boring a hole simultaneously, and perforation cracking etc.Perforation cracking will reduce anti-the squeezing of telescopic greatly and ruin performance, thereby shorten the life-span of oil well.In case the crack that perforation cracking produces is excessive, also can cause oil gas string layer, influences the exploitation of oil gas, causes enormous economic loss then.
The well-cased perforating crackle forms studies show that of mechanism, if make sleeve pipe have good anti-perforation cracking performance, sleeve pipe will possess higher impelling strength, good yield strength and plasticity and tiny and uniform crystal grain.
After the seventies in 20th century, people use vertical masonry joint resistance welding (ERW) steel pipe to replace seamless tube and make petroleum casing pipe.The raw material of ERW welded tube is a roll of steel plate, and being low-carbon microalloyed steel forms through controlled rolling and controlled cooling is rolling, and good obdurability is arranged, and ERW welded tube dimensional precision height, and the relative weldless steel tube of price is cheap.At present, J55 grade of steel (yield strength is the 380MPa level) among first group of the API SPEC 5CT, the large-scale application hot-rolled sheet coil is made surface string, and yield strength to be the N80 of 555MPa level still be weldless steel tube, producing the ERW welded tube with the hot continuous rolling coiled sheet still be blank.Because along with the intensity of steel improves, the impelling strength of steel, plasticity and welding property are all on a declining curve.
Traditional yield strength is that 555MPa level seamless petroleum casing pipe chemical ingredients and mechanical property are as follows:
| The trade mark | C | Si | Mn | Cr | P | S |
| 36Mn2V | 0.34～0.38 | 0.20～0.35 | 1.45～1.70 | ≤0.15 | ≤0.020 | ≤0.015 |
| Grade of steel | Rt0.5/MPa | Rm/MPa | A50/％ | 0℃Akv/J | Grain fineness number/level |
| N80 | 590～645MPa | 815～850MPa | 24～27 | 18～29 | 8 |
Because the carbon content height, the impelling strength of this steel is bad, and welding property is poor, and is easy to crack during perforation.Usually adopt steel pipe is carried out online normalizing or modified thermal treatment, but crystal grain thinning (about 8 grades of its grain fineness number) fundamentally improves impelling strength.And because the thermal treatment process production cycle is long, the expense height raises production cost.
Summary of the invention
At present yield strength be that the seamless casing dimensional precision of 555MPa level is not high, inhomogeneity of wall thickness even, the shortcoming of poor impact toughness, perforation cracking, the invention provides a kind of steel, be used to make the welded casing that yield strength is the 555MPa level, this sleeve pipe can overcome a series of shortcomings of seamless casing, and price is relatively cheap.
A kind of straight joint resistance welding oil annular tube steel, the chemical ingredients of steel (heat analysis) percentage is by weight counted: C0.04～0.20%, Si0.10～0.40%, Mn1.20～2.00%, Nb0.03～0.07%, Mo0.10～0.40%, Cu0～0.30%, Ni0～0.40%, B0.0005～0.0030%, Als0.010～0.050%, Ti≤0.030%, 0＜P≤0.025%, 0＜S≤0.005%, other is iron and inevitable tramp element.
The C content of this invention is limited in 0.04～0.20%.The C element is the main solution strengthening element of steel.But too high levels then worsens welding and impelling strength.The present invention has reduced the carbon content in the steel, makes it be controlled at a reasonable range, has both guaranteed its solid solution strengthening effect, does not reduce the welding and the impelling strength of steel simultaneously again.
Si content of the present invention is 0.10%～0.40%, and Si mainly improves the intensity of steel with the solution strengthening form, but content can not be too high, in order to avoid reduce the toughness and the welding property of steel.
Mn content of the present invention is controlled at 1.20%～2.00%.Mn is important solution strengthening element, simultaneously toughness is had some improvement.But Mn surpasses at 2.00% o'clock, is easy to produce tangible banded segregation in steel, and too low Mn then can not guarantee the intensity of steel plate.
P of the present invention, S content are: 0＜P≤0.025%, 0＜S≤0.005%, low P, S content are in order to guarantee high purity of steel, to obtain good impelling strength of this steel and corrosion resistance.
Cu mainly plays solid solution and precipitation strength effect in steel, but works as Cu content less than 0.30%, and its precipitation strength effect is not obvious.Mainly be the intensity that improves steel by solution strengthening.
Ni except having certain strengthening effect, can also improve the impelling strength of steel significantly in steel.Base material and welded heat affecting zone low-temperature flexibility are increased substantially.Ni can also effectively stop the hot-short check crack that causes of Cu.The sufficient quantity of Ni is 0～0.40% among the present invention.
The content of Mo is 0.10%～0.40%.Mo can increase hardening capacity, significantly improves the intensity of steel.But too much Mo can make the impelling strength of steel significantly worsen.So the content of Mo is controlled at 0.10%～0.40%.
The content of Nb is 0.03～0.07%.Nb is main by improving recrystallization temperature rice crystal grain thinning in steel, prevents grain coarsening.Simultaneously, Nb is strong carboritride forming element, can play precipitation strength in steel.The sufficient quantity of Nb is 0.03%～0.07% among the present invention.
The crystal grain of heat affected zone control when the adding of Ti helps welding, this is very favorable to the toughness of improving welded heat affecting zone.Ti is strong nitride forming element simultaneously, and the nitride of Ti is the pinning austenite grain boundary effectively, therefore helps to control growing up of austenite crystal, crystal grain thinning.The content of Ti is controlled at≤and 0.030%.
Als content of the present invention is controlled at 0.010～0.050%, and Al is the main deoxidant element and solid N element in the steel.Als content will cause the nitride inclusion of Al to increase greater than 0.050%, reduce the purity and the impelling strength of steel.Can not effectively consolidate N but the content of Al is too low.
The content of B is controlled at 0.0005～0.0030%.B can significantly improve the hardening capacity of steel, thereby obviously improves the intensity of steel.Mo element in B and the steel can significantly be postponed the perlitic transformation of steel together, makes steel obtain bainite structure under low cooling rate, thereby obtains good obdurability coupling.
The manufacture method of described straight joint resistance welding oil annular tube steel may further comprise the steps: converter smelting-RH vacuum outgas-LF stove refining-continuous casting-slab heating-rolling-control is cold-and batches, concrete parameter is controlled to be:
Process for making control:
(1) hot metal pretreatment: guarantee stove molten iron S content≤0.005%;
(2) external refining: the RH vacuum-treat, the treatment time is no less than 8 minutes;
(3) inclusion modification is handled: feeding CaSi line in ladle furnace, feed quantity 600～900 gram/tons, wire-feeding velocity 250～300m/min;
(4) the casting process superheating temperature is less than 20 ℃;
Yield strength is that the purity and the tissue homogeneous degree of the sleeve pipe steel to steel of 555MPa level requires very high.Because of this steel after ERW welding, if there are defectives such as inclusion or layering in the steel of weld seam periphery itself, then this welded tube is exactly a substandard product when UT (Ultrasonic Testing).Thereby cause the welded tube qualification rate to reduce.And the banded structure in the steel exceeds standard, and will have a strong impact on the anti-H of steel pipe
2S (HIC) corrosive nature, thus cause steel pipe to reduce work-ing life.Therefore, the control of process for making will be controlled by external refining, the abundant denaturing treatment of inclusion and strict superheating temperature exactly and improve slab quality, reduces the steel defective as far as possible.Go into stove molten iron S content≤0.005%th, in order to guarantee raw-material cleanliness factor.RH vacuum processing time deficiency, it is insufficient then to outgas.And CaSi line feeding mode is improper, and inclusion modification is just insufficient so.Casting process superheating temperature height causes the more serious center segregation of strand easily.
Cooling controlling and rolling controlling process control:
(1) slab reheat temperature is 1220 ± 30 ℃;
(2) finishing temperature is 780～860 ℃;
(3) coiling temperature is 520～640 ℃;
(4) 10～30 ℃/s of speed of cooling.
Cooling controlling and rolling controlling process control at first is the reheat process of control steel billet.Prevent that the reheat temperature is too high, in order to avoid AUSTENITE GRAIN COARSENING; Cross low, then fully solid solution of alloying element.Finish rolling stage control finishing temperature suppresses austenite and changes to proeutectoid ferrite more than Ar3.In coiling process subsequently, make supercooled austenite be transformed into middle temperature tissue by suitable temperature: bainite.Improve the intensity and the toughness of steel.
The yield strength that application the inventive method and described composition are made is the shortcoming that 555MPa level used for straight seam electric resistance welding petroleum steel pipe has overcome weldless steel tube welding property and poor impact toughness, prepared steel is the intensity height not only, and owing to reduced the carbon content in the steel, use the production of microalloyed steel cooling controlling and rolling controlling process simultaneously, the crystal grain of steel tiny (grain fineness number reaches more than 10 grades), homogeneous microstructure, steel have good impelling strength and welding property, and the dimensional precision of steel band is controlled well, and same coil thickness deviation can be controlled in ± 40 μ m.And have good corrosion resistance, anti-HIC test-results satisfies: CSR≤2%; CLR≤15%; CTR≤5%.While the method for the invention also has with short production cycle, and expense is low, and therefore the advantage that production cost is low is beneficial to and applies.
Embodiment
Embodiment 1:
A kind of straight joint resistance welding oil annular tube steel, the chemical ingredients of steel (heat analysis) percentage is by weight counted: C0.04～0.20%, Si0.10～0.40%, Mn1.20～2.00%, Nb0.03～0.07%, Mo0.10～0.40%, Cu0～0.30%, Ni0～0.40%, B0.0005～0.0030%, Als0.010～0.050%, Ti≤0.030%, 0＜P≤0.025%, 0＜S≤0.005%, other is iron and inevitable tramp element.
The manufacture method of above-mentioned steel may further comprise the steps: converter smelting-RH vacuum outgas-LF stove refining-continuous casting-slab heating-rolling-control is cold-and batches, concrete parameter is controlled to be:
Process for making control:
(1) hot metal pretreatment: guarantee stove molten iron S content≤0.005%;
(2) external refining: the RH vacuum-treat, the treatment time is no less than 8 minutes;
(3) inclusion modification is handled: feeding CaSi line in ladle furnace, feed quantity 600～900 gram/tons, wire-feeding velocity 250～300m/min;
(4) the casting process superheating temperature is less than 20 ℃;
Cooling controlling and rolling controlling process control:
(1) slab reheat temperature is 1220 ± 30 ℃;
(2) finishing temperature is 780～860 ℃;
(3) coiling temperature is 520～640 ℃;
(4) 10～30 ℃/s of speed of cooling.
Embodiment 2:
The difference of present embodiment and embodiment 1 is that the chemical ingredients of described steel (heat analysis) percentage is by weight counted: C0.04～0.08%, Si0.30～0.40%, Mn1.20～1.40%, Nb0.05～0.07%, Ti0～0.01%, Mo0.30～0.40%, Cu0～0.10%, Ni0.20～0.40%, B0.0005～0.0010%, P0.015～0.025%, S0.0001～0.001%, Als0.040～0.050%, other is iron and inevitable tramp element.
Embodiment 3:
The difference of present embodiment and embodiment 1 is that the chemical ingredients of described steel (heat analysis) percentage is by weight counted: C0.08～0.14%, Si0.20～0.30%, Mn1.40～1.60%, Nb0.04～0.05%, Ti0.01～0.02%, Mo0.20～0.30%, Cu0.10～0.20%, Ni0.10～0.20%, B0.0010～0.0020%, P0.008～0.015%, S0.001～0.003%, Als0.020～0.040%, other is iron and inevitable tramp element.
Embodiment 4:
The difference of present embodiment and embodiment 1 is that the chemical ingredients of described steel (heat analysis) percentage is by weight counted: C0.14～0.20%, Si0.10～0.20%, Mn1.60～2.00%, Nb0.03～0.04%, Ti0.02～0.03%, Mo0.10～0.20%, Cu0.20～0.30%, Ni0～0.10%, B0.0020～0.0030%, P0.001～0.008%, S0.003～0.005%, Als0.010～0.020%, other is iron and inevitable tramp element.
Embodiment 5:
Steel 1 in described steel chemical composition of present embodiment such as the table 1.The difference of its manufacture method and embodiment 1 is, adopts molten iron pre-desulfurization, smelts steel of the present invention on 250 tons of oxygen top and bottom combined blown converters, through the RH vacuum-treat, and through LHF ladle furnace hello Ca-Si line, inclusion is carried out denaturing treatment.Control continuous casting superheating temperature is lower than 20 ℃.1230 ℃ of rolling process steel billet reheat temperature, 830 ℃ of finishing temperatures, 550 ℃ of coiling temperatures, 13 ℃/s of speed of cooling.
As do not have additional description, manufacturing processed is identical with embodiment 1.
The thickness that the described method of present embodiment is produced hot rolled strip is 10mm, and steel 1 in mechanical property such as the table 2.
Embodiment 6:
Steel 2 in described steel chemical composition of present embodiment such as the table 1.The difference of its manufacture method and embodiment 1 is, adopts molten iron pre-desulfurization, smelts steel of the present invention on 250 tons of oxygen top and bottom combined blown converters, through the RH vacuum-treat, and through LHF ladle furnace hello Ca-Si line, inclusion is carried out denaturing treatment.Control continuous casting superheating temperature is lower than 20 ℃.1220 ℃ of rolling process steel billet reheat temperature, 840 ℃ of finishing temperatures, 580 ℃ of coiling temperatures, 15 ℃/s of speed of cooling.
As do not have additional description, manufacturing processed is identical with embodiment 1.
The thickness that the described method of present embodiment is produced hot rolled strip is 8mm, and steel 2 in mechanical property such as the table 2.
Steel melting chemical composition (Wt%) table 1
| Sequence number | C | Si | Mn | P | S | Nb | Ti | Cu | Mo | Ni | V | B | Als |
| Steel 1 | 0.06 | 0.20 | 1.58 | 0.020 | 0.003 | 0.05 | 0.015 | 0.17 | 018 | 0.18 | / | 0.002 | 0.023 |
| Steel 2 | 0.05 | 0.22 | 1.42 | 0.012 | 0.002 | 0.035 | 0.012 | / | 0.21 | 0.19 | / | 0.0014 | 0.020 |
The mechanical property table 2 of steel
| Sequence number | Thickness of slab/mm | R 10.5/ MPa | R m/ MPa | R 10.5/R m | A 50/％ | 0 ℃ of shock test | Grain fineness number/level | |
| Akv/J | SA/％ | |||||||
| Steel 1 | 10 | 613 | 761 | 0.80 | 24 | 135，130，131 | 100，100，100 | 11.5 |
| 132 | 100 | |||||||
| Steel 2 | 8 | 660 | 770 | 0.86 | 23 | 261，240，242 | 90，85，85 | 12 |
| 248 | 87 | |||||||
| The API requirement | 552-759 | ≥690 | / | 17 | ≥30 | / | / | |
Claims (5)
1. straight joint resistance welding oil annular tube steel, the chemical ingredients (heat analysis) that it is characterized in that steel percentage is by weight counted: C 0.04～0.20%, and Si 0.10～0.40%, Mn 1.20～2.00%, and Nb 0.03～0.07%, and Mo 0.10～0.40%, Cu 0～0.30%, Ni 0～0.40%, and B 0.0005～0.0030%, and Als 0.010～0.050%, Ti≤0.030%, 0＜P≤0.025%, 0＜S≤0.005%, other is iron and inevitable tramp element.
2. straight joint resistance welding oil annular tube steel according to claim 1, the chemical ingredients (heat analysis) that it is characterized in that steel percentage is by weight counted: C 0.04～0.08%, Si 0.30～0.40%, Mn 1.20～1.40%, Nb 0.05～0.07%, Ti 0～0.01%, Mo 0.30～0.40%, Cu 0～0.10%, and Ni 0.20～0.40%, and B 0.0005～0.0010%, P 0.015～0.025%, S 0.0001～0.001%, and Als 0.040～0.050%, and other is iron and inevitable tramp element.
3. straight joint resistance welding oil annular tube steel according to claim 1, the chemical ingredients (heat analysis) that it is characterized in that steel percentage is by weight counted: C 0.08～0.14%, Si 0.20～0.30%, Mn 1.40～1.60%, Nb 0.04～0.05%, Ti 0.01～0.02%, Mo 0.20～0.30%, Cu 0.10～0.20%, and Ni 0.10～0.20%, and B 0.0010～0.0020%, P 0.008～0.015%, S 0.001～0.003%, and Als 0.020～0.040%, and other is iron and inevitable tramp element.
4. straight joint resistance welding oil annular tube steel according to claim 1, the chemical ingredients (heat analysis) that it is characterized in that steel percentage is by weight counted: C 0.14～0.20%, Si 0.10～0.20%, Mn 1.60～2.00%, Nb 0.03～0.04%, Ti 0.02～0.03%, Mo 0.10～0.20%, Cu 0.20～0.30%, and Ni 0～0.10%, and B 0.0020～0.0030%, P 0.001～0.008%, S 0.003～0.005%, and Als 0.010～0.020%, and other is iron and inevitable tramp element.
5. the manufacture method of the described straight joint resistance welding oil annular tube steel of claim 1 is characterized in that may further comprise the steps: converter smelting-RH vacuum outgas-LF stove refining-continuous casting-slab heating-rolling-control is cold-and batches, concrete parameter is controlled to be:
Process for making control:
(1) hot metal pretreatment: guarantee stove molten iron S content≤0.005%;
(2) external refining: the RH vacuum-treat, the treatment time is no less than 8 minutes;
(3) inclusion modification is handled: feeding CaSi line in ladle furnace, feed quantity 600～900 gram/tons, wire-feeding velocity 250～300m/min;
(4) the casting process superheating temperature is less than 20 ℃;
Cooling controlling and rolling controlling process control:
(1) slab reheat temperature is 1220 ± 30 ℃;
(2) finishing temperature is 780～860 ℃;
(3) coiling temperature is 520～640 ℃;
(4) 10～30 ℃/s of speed of cooling.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNA2007100536555A CN101139682A (en) | 2007-10-26 | 2007-10-26 | Straight joint resistance welding oil annular tube steel and manufacturing method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNA2007100536555A CN101139682A (en) | 2007-10-26 | 2007-10-26 | Straight joint resistance welding oil annular tube steel and manufacturing method thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN101139682A true CN101139682A (en) | 2008-03-12 |
Family
ID=39191787
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNA2007100536555A Pending CN101139682A (en) | 2007-10-26 | 2007-10-26 | Straight joint resistance welding oil annular tube steel and manufacturing method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN101139682A (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101798654A (en) * | 2010-04-09 | 2010-08-11 | 中国石油天然气集团公司 | Steel used for straight seam electric resistance welding petroleum casing and casing manufacturing method |
| CN102021494B (en) * | 2009-09-23 | 2012-11-14 | 宝山钢铁股份有限公司 | Weather resistant thick steel plate and manufacturing method thereof |
| CN105316558A (en) * | 2014-07-01 | 2016-02-10 | 本钢板材股份有限公司 | Preparation method of boron-containing steel preventing casting blank corner cracking |
| CN106567001A (en) * | 2016-11-15 | 2017-04-19 | 马鞍山钢铁股份有限公司 | Steel for re-cold-drawing of ERW welding pipe and hot rolling plate roll and preparing method of steel |
| CN106715744A (en) * | 2014-09-25 | 2017-05-24 | 杰富意钢铁株式会社 | Steel strip for electric-resistance-welded steel pipe, electric-resistance-welded steel pipe, and process for producing steel strip for electric-resistance-welded steel pipe |
| CN110055469A (en) * | 2019-04-15 | 2019-07-26 | 山东钢铁股份有限公司 | It is weather-resistance hot rolled H-shaped and preparation method thereof that one kind exempting from coating steel construction antidetonation |
-
2007
- 2007-10-26 CN CNA2007100536555A patent/CN101139682A/en active Pending
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102021494B (en) * | 2009-09-23 | 2012-11-14 | 宝山钢铁股份有限公司 | Weather resistant thick steel plate and manufacturing method thereof |
| CN101798654A (en) * | 2010-04-09 | 2010-08-11 | 中国石油天然气集团公司 | Steel used for straight seam electric resistance welding petroleum casing and casing manufacturing method |
| CN105316558A (en) * | 2014-07-01 | 2016-02-10 | 本钢板材股份有限公司 | Preparation method of boron-containing steel preventing casting blank corner cracking |
| CN105316558B (en) * | 2014-07-01 | 2017-05-03 | 本钢板材股份有限公司 | Preparation method of boron-containing steel preventing casting blank corner cracking |
| CN106715744A (en) * | 2014-09-25 | 2017-05-24 | 杰富意钢铁株式会社 | Steel strip for electric-resistance-welded steel pipe, electric-resistance-welded steel pipe, and process for producing steel strip for electric-resistance-welded steel pipe |
| CN106567001A (en) * | 2016-11-15 | 2017-04-19 | 马鞍山钢铁股份有限公司 | Steel for re-cold-drawing of ERW welding pipe and hot rolling plate roll and preparing method of steel |
| CN106567001B (en) * | 2016-11-15 | 2019-02-19 | 马鞍山钢铁股份有限公司 | Cold-drawn ERW welds tube steel and its hot-rolled sheet coil and preparation method to one kind again |
| CN110055469A (en) * | 2019-04-15 | 2019-07-26 | 山东钢铁股份有限公司 | It is weather-resistance hot rolled H-shaped and preparation method thereof that one kind exempting from coating steel construction antidetonation |
| CN110055469B (en) * | 2019-04-15 | 2020-09-18 | 山东钢铁股份有限公司 | Coating-free anti-seismic weather-resistant hot-rolled H-shaped steel for steel structure and preparation method thereof |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101287853B (en) | Seamless steel pipe for line pipe and method for producing same | |
| CN101634001B (en) | CT90-class steel for continuous oil pipe and method for manufacturing same | |
| CN103069020B (en) | Oil well electric welded steel pipe and the manufacture method of oil well electric welded steel pipe | |
| CN101440461B (en) | A kind of oil well gas corrosion-resistant sucker rod steel and its manufacturing method | |
| CN103290339B (en) | High-strength steel plate for 800MPa hydropower station pressure pipeline and production method thereof | |
| CN103834874B (en) | Heavy wall height DWTT performance X65-70 subsea pipeline steel and manufacture method | |
| CN101368251B (en) | Steel plate for large-thickness hydrogen-contacting equipment and its production technology | |
| CN109957712B (en) | Low-hardness X70M pipeline steel hot-rolled plate coil and manufacturing method thereof | |
| CN104789866B (en) | 630MPa level quenching and tempering type low temperature spherical tank high-strength and high-ductility steel plate and its manufacture method | |
| CN102560284B (en) | High-strength high-toughness X100 pipeline steel hot-rolled steel strip and manufacturing method thereof | |
| CN106811700B (en) | Thick acid-resistant X60MS hot-rolled coil and manufacturing method thereof | |
| CN102021497A (en) | A kind of X80 pipeline steel hot-rolled coil and its manufacturing method | |
| CN106544590A (en) | 1000MPa grade high ductilities high-performance uniformity easily welds super-thick steel plate and its manufacture method | |
| CN101353765A (en) | Steel for CT80 grade coiled tubing, and manufacturing method and use thereof | |
| CN104878291B (en) | A kind of yield strength 350 MPa seamless line pipe and preparation method thereof | |
| CN103469098A (en) | X80 pipeline steel with good HIC (hydrogen induced cracking) resistance and production method thereof | |
| CN101139682A (en) | Straight joint resistance welding oil annular tube steel and manufacturing method thereof | |
| CN101168823B (en) | Steel for high-plasticity continuous oil pipe and manufacturing method thereof | |
| CN104894492A (en) | Ultralow-temperature, large-diameter and WPHY80-level steel plate special for three-way pipe fitting and production method of steel plate | |
| CN104630655A (en) | Extra-thick steel plate having excellent balance between strength and toughness and used for welded structure and production process thereof | |
| CN100366778C (en) | Steel in use for fire resistant, heat insulated oil line, and preparation method | |
| US20090065102A1 (en) | High Strength Seamless Steel Pipe for Machine Structure Use Superior in Toughness and Weldability, and Method of Production of The Same | |
| CN102586690A (en) | Wear-resisting steel for slurry delivery pipe line and production method of wear-resisting steel | |
| CN112143968A (en) | Ultra-thick X70M-grade double-resistance pipeline steel plate and manufacturing method thereof | |
| CN105112810A (en) | Steel for high heat input resisting welding and preparation 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 |
Open date: 20080312 |