CN109504827A

CN109504827A - A kind of high corrosion resisting stainless steel of cupric tantalum cobalt and its process and heat treatment method

Info

Publication number: CN109504827A
Application number: CN201811576409.2A
Authority: CN
Inventors: 罗丰华; 赵忠新; 吴子恺; 黄小琴; 王翔; 赵甲正
Original assignee: Central South University
Current assignee: Central South University
Priority date: 2018-12-22
Filing date: 2018-12-22
Publication date: 2019-03-22

Abstract

A kind of high corrosion resisting stainless steel of cupric tantalum cobalt and its process and heat treatment method, alloying element mass percent are as follows: C≤0.08, Ni=11.0~15.0, Cr=18.0~20.0, Mo=3.0~4.0, Ta≤1.20, Cu=0.2~0.8, Co=0.1~0.5, Mn≤2.0, Si≤1.0, P≤0.035, S≤0.030, wherein 15.06 × (C-0.01)≤Ta≤15.06 × C, surplus Fe.Through thermal deformation cogging and cold deformation, TaC is broken, disperse, grain coarsening after higher temperature solid solution.Contain 5 × 10 for 80 DEG C under the conditions of logical oxygen^‑6F^‑0.5mol/L H₂SO₄Corrosion electric current density is 1.08~1.35 μ A/cm in electrolyte², suitable with the stainless steel double polar plate material through surface covering.Have the characteristics that soft and high extension, conducive to the molding of bipolar plate runner.

Description

A kind of high corrosion resisting stainless steel of cupric tantalum cobalt and its process and heat treatment method

Technical field

The invention belongs to field of Austenitic stainless steel, be related to high corrosion-resistant austenitic stainless steel ingredient design and processing, Heat-treating methods can be widely used for the energy, electric power, chemical field and daily life.

Technical background

Fuel cell is that a kind of chemical energy by between hydrogen fuel and oxidant is directly translated into electric energy by electrode reaction Device.Since its is high-efficient, pollution is small, the time of founding the factory is short, reliability and maintainability are good, be after hydroelectric generation, thermal power generation, Forth generation generation technology after nuclear power.In numerous fuel cells, Proton Exchange Membrane Fuel Cells is later one of development Kind new fuel cell, but its is with the fastest developing speed.

In a fuel cell, play support, afflux, segmentation oxidant and reducing agent and Oxidizing and Reducing Agents is guided to exist The conductive separator plate that electrode surface flows in battery is referred to as bipolar plates.Inside fuel cell unit, the function and feature of bipolar plates To separate oxidant and reducing agent, therefore bipolar plates must have the function of choke, cannot use porous air pervious material；Make with afflux With, it is necessary to it is the good conductor of electricity.Environment locating for bipolar plates exists simultaneously oxide isolation such as oxygen and reducing medium such as hydrogen, institute With bipolar plate material must be able under these conditions in the potential range of its work have resistance to corrosion.Bipolar plates should be heat Good conductor, to ensure that the temperature of battery pack is uniformly distributed and the implementation of heat extraction scheme.

The two sides of bipolar plates, which process or are equipped with, makes the equally distributed runner of reaction gas, i.e., so-called flow field, and flow field should be true It protects reaction gas to be evenly distributed everywhere in entire electrode, bipolar plates also play support membrane electrode in fuel cell unit, keep electricity The stable effect of pond pile structure, this requires plate materials to have certain intensity, and bipolar plate material answers that light, intensity is good, simultaneously And it is suitable for batch production.

It is the principal element for being difficult to commercial applications at present that cost is too high, and lower quality is than high power and volume ratio Power is also its big obstacle in automobile power power supply application aspect.Generally, not only Zhan is total for the expense of bipolar plates in cost Cost, and occupy cell reaction heap weight.Therefore, seek and design inexpensive, lightweight, plate it is thin, have good mechanical property Energy, high surface and bulk conductivity, low-permeable, resistant material and lower-cost technology of preparing are bipolar plates development Target.

The bipolar plates being widely used at present have graphite plate, metal plate and composite dual-electrode plates.

Graphite bi-polar plate has good rotproofness, electric conductivity, and the contact resistance on surface is small.Thus in a variety of materials In bipolar plates, the discharge performance of graphite bi-polar plate is best, is often used as developing the reference frame of other new material bipolar plates.But stone The porosity of ink is big, mechanical strength is low, brittleness is big, poor processability, in order to prevent working gas from seeping bipolar plates and meet machine The thickness of tool Intensity Design, graphite bi-polar plate should be thicker, and it is larger that this allows for its volume and weight, to limit graphite bi-polar The practical application of plate.The auto industry of especially great application prospect, it is desirable that necessary gravimetric specific energy with higher, and can It is subjected to the vibration of automobile during high speed exercise.

Not only obdurability is good for metal material, but also machining property, electric conductivity, thermal conductivity, compactness are preferable, can be with For making very thin bipolar plates.But all metals all have one disadvantage in that that is, corrosion resistance is poor, this allows for needing to use Various technologies are improved its performance with means.

The electrochemical behavior of 316L, 317L, 349 and 904L stainless steel are carried out pair under analog fuel cell operating conditions Than the corrosion resistance sequence obtained are as follows: 349 > 904L > 317L > 316L shows that chromium content is higher, and corrosion resistance is stronger.Without The passivation layer that the 316L stainless steel of surface treatment is formed in fuel cell environment will lead to contact resistance increase, not be able to satisfy double The requirement of plate material.Therefore, the corrosion resistance to enhance stainless steel, it is necessary to or painting plating modified to its surface.

The corrosion occurred in fuel cell operation to solve stainless steel and titanium plate as bipolar plate material and surface Problem of passivation, using the methods of thermal jet, silk-screen printing, physical vapour deposition (PVD), chemical vapor deposition, plating, chemical plating and sputtering, Such surface treatment not only reduces contact resistance, but also improves the corrosion resistance of bipolar plates.

At simulated battery cathode working environment (0.8V/NHE, 80 DEG C, air), to being coated with 10nm thickness nm Au 316L stainless steel carries out constant potential polarization for 24 hours, and corrosion electric current density is less than 1 μ A/cm².It is constantly under anode-context Passive state.After bipolar plates are made in its punching press, in the case where assembling force is 0.6MPa, contact resistance is 6.3m Ω cm²。

Niobium metal is plated on 316L stainless steel using ion implantation technique, in simulation Proton Exchange Membrane Fuel Cells building ring (0.5mol/L H under border₂SO₄+ 2ppm HF, 80 DEG C), the stainless steel watch after ion implanting 2h reveals best performance, electrokinetic potential Testing its lower passive current density is 6 μ A/cm²；

The amorphous of 3 μ m-thicks densification is prepared on 316L stainless steel using closed field unbalanced magnetron sputtering ion plating method Carbon-coating.In the case where assembling force is 1.2~2.1MPa, contact resistance is 8.3~5.2m Ω cm², and the contact resistance of graphite is 10.4~5.4m Ω cm².(0.5mol/L, H under simulated battery working environment₂SO₄+ 2ppm HF, 80 DEG C), it is moved Potential test, cathode passive current density are 3.56 μ A/cm²。

The features such as in the metal material of all researchs, stainless steel material is cheap with its, solid durable, becomes earliest Metal material for bipolar plates.The corrosion resistance of stainless steel material be largely determined by the formed passivation layer in its surface at Point and structure, and be passivated composition of layer and structure and determined again by the chemical component of stainless steel, therefore suitably stainless steel material alloy Change and organizational controls, have certain influence to its corrosion resisting property.

Summary of the invention

The object of the present invention is to provide a kind of high corrosion resisting stainless steel of cupric tantalum cobalt and its process and heat treatment methods.The present invention Its technical problem is solved the technical scheme adopted is that adding strong carbon on the basis of 317L austenitic stainless steel alloy ingredient Solid solution element copper (Cu), cobalt (Co), abbreviation 317L-TGT stainless steel under compound formation element tantalum (Ta) and high temperature.Its specific ingredient (mass percent) are as follows: C≤0.08, Ni=11.0~15.0, Cr=18.0~20.0, Mo=3.0~4.0, Ta≤1.20, Cu =0.2~0.8, Co=0.1~0.5, Mn≤2.0, Si≤1.0, P≤0.035, S≤0.030, wherein 15.06 × (C-0.01) ≤ Ta≤15.06 × C, Fe=surplus.It after alloy smelting, is handled through overheating deforming cogging and cold deformation, so that the TaC formed is obtained With sufficiently broken, Dispersed precipitate, then by higher temperature solid solution, coarse grain austenite structure is obtained, is made it have more high-strength Degree and corrosion resistance.

317L is U.S.'s trade mark, and corresponding China's stainless steel trade mark is 00Cr19Ni13Mo3；317 stainless steel plates are with respect to 316L Stainless steel plate has good sea water resistance and SCC resistance, the performance indicator of plate are as follows: yield strength >=205MPa, tension Intensity >=520MPa, elongation >=35%, hardness≤HV200.

Contain the C not higher than 0.08% in 317L stainless steel.C in austenitic stainless steel is imitated with stronger solution strengthening Fruit, but C is easy to form cementite Fe in conjunction with Fe₃C is precipitated in lamella, the corrosion resistance of stainless steel is caused to be difficult to improve.Therefore, Carbide Ta is added in the alloy, the spherical particle TaC compound of high stability is formed, so that austenite The solid solution content of practical C is greatly lowered in crystal grain, improves the corrosion resistance of stainless steel.Since the atomic weight of Ta is 180.95, and C Atomic weight be 12.01, the atomic weight ratio of Ta, C is 15.06, as 15.06 × (C-0.01)≤Ta≤15.06 × C, such as C When content is 0.08%, the content of Ta is 1.05%~1.20%, and the solid solution content of practical C is less than in austenite grain 0.01%, and the surplus of Ta element is not had.

Cu is non-carbide forming element, is added in steel and will form substitution solid solution.The Cu of every addition 1.0% can in steel The solution strengthening effect of 38~70MPa is generated, and copper adds the increment that caused yield strength increment is higher than tensile strength, And then the yield tensile ratio of steel can be improved significantly.The Cu ion for not luring steel surface to dissolve out can destroy bacterium internal protein structure, Inhibit the duplication and the synthesis of related protein/enzyme of DNA of bacteria, destroys the metabolic activity in bacterium, so that bacterium is lost activity, lead Cause bacterial death.Therefore 1~3%Cu is often added in some weathering steel, improves the corrosiveness of the resistance to marine environment of alloy.

A small amount of Cu is added in the present invention, the deficiency of C element when being to make up high-temperature heat treatment there are one significance. There are a large amount of Cr, Ni element in austenitic stainless steel, the segregation of Cr, Ni element be also cause the corrosion resistance of stainless steel be difficult into The main reason for one step improves.Therefore it needs to promote Cr, Ni to spread and homogenize in soak, and the presence of C element, have Conducive to the diffusivity for improving alloying element.Due to being added to carbide in the present invention, so that austenite grain Middle C solid solution content is very low, is unfavorable for homogenizing, it is therefore desirable to supplement a small amount of Cu, improve diffusivity, overcome Cr, Ni element Segregation further increases corrosion resistance.

Co is the element of non-carbide, is ferrite former, can form continuous solid solution with ferrite.Cobalt can drop The harden ability of low steel, cobalt can increase diffusion velocity of the carbon in austenite, to accelerate phase transition process, reduce the through hardening of steel Property.Cobalt not only accelerates the high-temperature phase-change process (austenite → pearlite) of steel, and influence middle temperature transformation process (austenite → Bainite).Co is added on a small quantity in austenitic stainless steel, phase-state change will not be caused, since the atomic radius of cobalt is 1.26, slightly Less than the atomic radius 1.27 of iron, therefore the Co atom being dissolved into Fe matrix is capable of forming tensile stress field, reduces stainless steel Hardness.

Bipolar plates two sides have and make the equally distributed runner of reaction gas, i.e., so-called flow field.These runners are by being rolled into Type obtains, and bipolar plate material hardness is low, can reduce the rebound generated when calendering and stress is concentrated.Co reduces the hard of stainless steel Degree, is conducive to the processing in flow field.

The preparation method of the 317L-TGT stainless steel includes following key step:

(1) smelting and casting of 317L-TGT stainless steel

Choose electrical pure iron, crome metal piece, metal nickel plate, metal molybdenum, stainless steel waste material, fine copper plate, pure cobalt piece, ferro tantalum or Metal tantalum, graphite block are that raw material is cast into alloy cast ingot after electric arc melting or induction melting.

It, should not be raw using stainless steel industries such as Converter vacuum oxygen decarburization methods since alloy is added to the elements such as Cu, Ta, Co Production method can only prepare alloy using electric arc melting or induction melting method.It takes vacuum or argon gas to protect when melting, avoids oxygen Change.

Stainless steel waste material is mainly that 316,316L, 317 etc. have the austenitic stainless steel of nickelic, Gao Ge, high molybdenum content useless Material, then with electrical pure iron, crome metal piece, metal nickel plate, metal molybdenum, fine copper plate, pure cobalt piece, ferro tantalum or metal tantalum, graphite block etc. Raw material, the alloyage in the composition range of the 317L-TGT stainless steel control C, Cr, Ni, Cu, Co, Ta, Mo in alloy Equal essential elements, and the impurity elements such as Mn, Si, P, S are guaranteed by the purity of raw material.

Bath temperature is kept for 1700 DEG C ± 20 DEG C when melting；Molten steel calmness 5~10 minutes before being poured, molten steel 1550 DEG C ± 50 DEG C, vacuum or argon for protecting pouring.According to subsequent product specification needs, the side's of being cast as ingot or billet.

(2) hot rolling cogging

Plate uses flat roll mill hot rolling cogging, and hot rolling scheme is that slab is heated to 1280 DEG C ± 10 DEG C, and heat preservation 3~5 is small When after come out of the stove rolling, hot rolling start temperature is 1180 DEG C ± 20 DEG C, finishing temperature >=950 DEG C.Plate hot rolling is always lower to measure >=60%.

Hot forging, groove rolling or universal rolling cogging can be used in pipe, stick, line, profile and cold punching part, ingot casting.

(3) cold-rolling deformation

Plate uses cold-rolling deformation, cold rolling overall reduction >=80%.

The purpose of hot rolling and cold rolling is that the carbide in alloy is sufficiently broken；After big cold rolling reduction advantageously ensures that Coarse brilliant tissue is formed when continuous heat treatment.

Pipe, stick, line, profile can be used reciprocating type tube rolling, groove rolling, universal rolling or the method dialled drawn to carry out cold change Shape obtains size, the specification of product requirement；The stainless steel parts that mechanical industry needs can also use thermal deformation cogging raw material, It is obtained again by cold stamping.

(4) high-temperature heat treatment

It after cold deformation, is made annealing treatment at 1085 DEG C ± 30 DEG C, soaking time is 30 minutes~120 minutes, when heating Using the inert gas shieldings such as vacuum or argon gas, nitrogen, helium；After annealing, using the gases such as water, oil or argon gas, nitrogen helium Medium is quickly cooled down.

The purpose of soak is to form coarse recrystal grain, so that breaked spherical particle carbide is from crystal boundary It is transferred to inside coarse recrystal grain, to mitigate grain boundary corrosion tendency.It is quickly cooled down in addition to can be to avoid a small amount of remnants Outside the crystal boundary of carbide is precipitated, most important purpose is to control the segregation of Cu element, improves the solid solubility of Cu element, obtains high Intensity and hardness.

According to the requirement of the size of product and Surface Quality, cooling medium is selected, when product size is larger, can be adopted The liquid mediums such as water intaking, oil, which are realized, to be quickly cooled down, and thin plate or small part can take the fast quickly cooling of the gas mediums such as argon gas, nitrogen helium But.

The implementation of above-mentioned high-temperature heat treatment method can be used heating in vacuum-air quenching, laser heating-water hardening, continuously add Heat-high pressure gas quenching, gas shield heating-water (oil) are quenched.Carried out after annealing aligning or setting treatment, aligning or sizing at The deflection of reason should be less than 2%.

317L-TGT stainless steel by above-mentioned high-temperature heat treatment is corroded using Ta Feier (Tafel) line extrapolation Electric current as the foundation of comparative alloy corrosion resistance, and measures the hardness and tensile mechanical properties of alloy.

Ta Feier (Tafel) line extrapolation is a kind of method for measuring corrosion rate.Way is that electricity is made in metal sample Pole is immersed in corrosive medium, is measured volt-ampere (E~I) data of stable state, is made log | I |~E figure, and by the straight of negative anodic polarization curve Line part extends.Corresponding gained intersection point is logI_cor, by corrosion current I_corDivided by the sample area of prior precise measurement S₀To get corrosion rate.This method is quickly time saving, the measurement suitable for metal homogeneous corrosion.

It simulates under Proton Exchange Membrane Fuel Cells working environment, therefore selects 80 DEG C to carry out corrosive nature as test temperature Comparison.The specific determination condition of corrosion rate are as follows: with 1cm²Stainless steel is working electrode, using saturated calomel electrode as reference electricity Pole, using platinized platinum as auxiliary electrode；Containing 5 × 10^-6F^-0.5mol/L H₂SO₄Electrolyte is heated to 80 DEG C with water bath, and to electricity Oxygen is passed through with the flow velocity of 20ml/min in solution liquid；Linear sweep voltametry, sweep speed 2mV/s are carried out to sample.With electrification The potentiostat function of learning constant potential tester or electrochemical workstation completes measurement, and the test software using instrument is to measuring Polarization curve carries out Ta Feier (Tafel) fitting, obtains corrosion current.The 317L stainless steel of above method measurement is rotten in room temperature Erosion electric current is 37 μ A/cm², it is 830 μ A/cm at 80 DEG C²。

Of the invention is mainly characterized by the basis of 317L stainless steel alloy, adds carbide Ta, drop The solid solubility of practical C in low austenite grain；It adds Cu element and improves High temperature diffusion ability, avoid Cr, Ni Element segregation；Addition Co element reduces stainless steel hardness；Subsequently through thermal deformation, cold deformation, causes carbide broken, is quenched by high temperature, Coarse grain is formed, so that alloy softens, and there are superior anti-corrosion abilities.317L-TGT alloy after high temperature quenching treatment For corrosion current under the conditions of logical oxygen, 80 DEG C contain 5 × 10^-6F^-0.5mol/L H₂SO₄It is 1.08~1.35 μ A/ in electrolyte cm², corrosion rate is greatly lowered, suitable with the corrosion rate of the bipolar plate of stainless steel through surface coated treatment.Hardness is 169 ~178HV1, yield strength are 187~197MPa, and tensile strength is 587~605MPa, and elongation percentage 37~42% has low hard Degree and high extension feature, are particularly conducive to the forming processes of bipolar plate runner.

Detailed description of the invention

2 corrosion surface electron microscope scanning figure of Fig. 1 present example；

3 polarization curve of Fig. 2 present example；

4 tensile mechanical properties curve graph of Fig. 3 present example；

Specific embodiment

Various method of smelting of the invention, casting method are not limited by following examples, any to want in right of the invention The improvements and changes in range for asking book claimed are all within protection scope of the present invention.

Select electrical pure iron, crome metal piece, metal nickel plate, metal molybdenum, stainless steel waste material, fine copper plate, pure cobalt piece, ferro tantalum or Metal tantalum, graphite block are raw material, are configured to alloy in the composition range that invention requires.

For the requirement of shape, dimensions and surface quality, prepared stainless steel and its part are subsequent that machine can be used Tool processing, polishing and corresponding chemical cleaning and polishing treatment, the present invention is not specifically limited.

Embodiment 1

Choosing electrical pure iron, crome metal piece, metal nickel plate, metal molybdenum, fine copper plate, pure cobalt piece, ferro tantalum, graphite block is original Material, the stainless composition of steel of configuration are as follows: C=0.05, Ni=12.0, Cr=19.0, Mo=3.0, Ta=0.70, Cu=0.4, Co =0.1, Mn=0.8, Si=0.5, P≤0.035, S≤0.030, Fe=surplus.

After weighing good corresponding raw material according to component requirements proportion, argon arc melting, bath temperature is protected when melting Hold 1720 DEG C；Calm 10 minutes of molten steel before being poured, molten steel is at 1600 DEG C, argon for protecting pouring.

Plate uses flat roll mill hot rolling cogging, and hot rolling scheme is that slab is heated to 1290 DEG C, and heat preservation is come out of the stove after 5 hours rolls System, hot rolling start temperature are 1190 DEG C, and finishing temperature is 950 DEG C.Always lower amount is 60% to plate hot rolling.

Plate uses cold-rolling deformation, and cold rolling overall reduction is 80%.

Plate is made annealing treatment at 1115 DEG C, and soaking time is 30 minutes, is protected when heating using argon gas；After annealing, Using water quenching cooling.

For the corrosion current of 317L-TGT alloy after high temperature quenching treatment under the conditions of logical oxygen, 80 DEG C contain 5 × 10^-6F^-'s The H of 0.5mol/L₂SO₄It is 1.08 μ A/cm in electrolyte².The hardness of alloy is 170HV, yield strength 191MPa, and tension is strong Degree is 600MPa, elongation percentage 38%.

Embodiment 2

Choosing 316L stainless steel waste material, metal molybdenum, fine copper plate, pure cobalt piece, metal tantalum, graphite block is raw material, and configuration is not The composition of steel that becomes rusty is as follows: C=0.06, Ni=15.0, Cr=18.5, Mo=3.2, Ta=0.80, Cu=0.5, Co=0.5, Mn= 1.3, Si=0.3, P≤0.035, S≤0.030, Fe=surplus.

After weighing good corresponding raw material according to component requirements proportion, through vacuum induction melting, bath temperature is kept when melting 1680℃；Calm 5 minutes of molten steel before being poured, molten steel is at 1500 DEG C, vacuum pouring.

Plate uses flat roll mill hot rolling cogging, and hot rolling scheme is that slab is heated to 1270 DEG C, and heat preservation is come out of the stove after 5 hours rolls System, hot rolling start temperature are 1160 DEG C, and finishing temperature is 1000 DEG C.Always lower amount is 65% to plate hot rolling.

Plate uses cold-rolling deformation, and cold rolling overall reduction is 85%.

Plate keeps the temperature 120 minutes at 1055 DEG C, and helium air quenching is taken after vacuum annealing.

For the corrosion current of 317L-TGT alloy after high temperature quenching treatment under the conditions of logical oxygen, 80 DEG C contain 5 × 10^-6F^-'s The H of 0.5mol/L₂SO₄It is 1.21 μ A/cm in electrolyte², Fig. 1 is the electron microscope scanning figure of its corrosion surface.Alloy it is hard Degree is 176HV, yield strength 194MPa, tensile strength 603MPa, elongation percentage 39%.

From fig. 1, it can be seen that corrosion surface is very smooth, crystal grain is very coarse, does not remain corrosion product, but has many smooth Aperture, is mainly distributed on intra-die, and crystal boundary is seldom.It falls off this is because the tiny carbide in surface preferentially corrodes, it is remaining Smooth surface is homogeneous, and crystal boundary is clear, has stronger resistance to corrosion

Embodiment 3

Choose electrical pure iron, crome metal piece, metal nickel plate, metal molybdenum, 316 stainless steel waste materials, fine copper plate, pure cobalt piece, gold Category tantalum is raw material, and the stainless composition of steel of configuration is as follows: C=0.03, Ni=14.5, Cr=18.0, Mo=4.0, Ta=0.45, Cu =0.2, Co=0.2, Mn=1.2, Si=0.8, P≤0.035, S≤0.030, Fe=surplus.

After weighing good corresponding raw material according to component requirements proportion, induction melting is protected through argon gas, bath temperature when melting Kept for 1700 DEG C；Calm 7 minutes of molten steel before being poured, molten steel is at 1550 DEG C, argon for protecting pouring.

Plate uses flat roll mill hot rolling cogging, and hot rolling scheme is that slab is heated to 1280 DEG C, and heat preservation is come out of the stove after 4 hours rolls System, hot rolling start temperature are 1180 DEG C, and finishing temperature is 980 DEG C.Always lower amount is 70% to plate hot rolling.

Plate uses cold-rolling deformation, and cold rolling overall reduction is 82%.

Plate is made annealing treatment at 1100 DEG C, and soaking time is 60 minutes, using nitrogen protection；Take continuous annealing furnace Annealing, is quickly cooled down after annealing with high pressure nitrogen.

For the corrosion current of 317L-TGT alloy after high temperature quenching treatment under the conditions of logical oxygen, 80 DEG C contain 5 × 10^-6F^-'s The H of 0.5mol/L₂SO₄It is 1.29 μ A/cm in electrolyte², polarization curve is shown in Fig. 2.The hardness of alloy is 172HV, yield strength For 195MPa, tensile strength 587MPa, elongation percentage 42%.

Embodiment 4

Choosing 317L stainless steel waste material, fine copper plate, pure cobalt piece, ferro tantalum is raw material, and the stainless composition of steel of configuration is as follows: C= 0.04, Ni=11.0, Cr=18.8, Mo=3.7, Ta=0.56, Cu=0.3, Co=0.3, Mn=1.2, Si=0.7, P≤ 0.035, S≤0.030, Fe=surplus.

After weighing good corresponding raw material according to component requirements proportion, through vacuum induction melting, bath temperature is kept when melting 1690℃；Calm 8 minutes of molten steel before being poured, molten steel is at 1550 DEG C, vacuum pouring.The side's of being cast as ingot.

Ingot casting uses hot rolling cogging, and hot rolling scheme is that slab is heated to 1290 DEG C, rolling of coming out of the stove after keeping the temperature 3 hours, Hot rolling initial forging temperature is 1200 DEG C, and finishing temperature is 1020 DEG C, and always lower amount is 68% for hot rolling.

Plate uses cold-rolling deformation, and cold rolling overall reduction is 85%.

It is made annealing treatment after cold rolling at 1105 DEG C, soaking time is 45 minutes, and vacuum annealing, oil quenching are used when heating.

For the corrosion current of 317L-TGT alloy after high temperature quenching treatment under the conditions of logical oxygen, 80 DEG C contain 5 × 10^-6F^-'s The H of 0.5mol/L₂SO₄It is 1.13 μ A/cm in electrolyte².The hardness of alloy is 169HV1, yield strength 195MPa, and tension is strong Spending is 605MPa, elongation percentage 37%, and tensile mechanical properties curve is shown in Fig. 3.

Embodiment 5

Choosing electrical pure iron, crome metal piece, metal nickel plate, metal molybdenum, fine copper plate, pure cobalt piece, ferro tantalum, graphite block is original Material, the stainless composition of steel of configuration are as follows: C=0.07, Ni=13.0, Cr=20.0, Mo=3.5, Ta=1.00, Cu=0.7, Co =0.2, Mn=0.6, Si=0.3, P≤0.035, S≤0.030, Fe=surplus.

After weighing good corresponding raw material according to component requirements proportion, through argon atmosphere electric arc melting, bath temperature when melting Kept for 1700 DEG C；Calm 6 minutes of molten steel before being poured, molten steel is at 1580 DEG C, argon for protecting pouring.Plate uses flat roll mill hot rolling Cogging, hot rolling scheme are that slab is heated to 1280 DEG C, and rolling of coming out of the stove after keeping the temperature 4 hours, hot rolling start temperature is 1180 DEG C, finish to gauge Temperature is 1000 DEG C.Always lower amount is 65% to plate hot rolling.

Plate uses cold-rolling deformation, and cold rolling overall reduction is 85%.

Plate is made annealing treatment at 1100 DEG C, and soaking time is 90 minutes, is heated and is used vacuum protection when keeping the temperature, protects High pressure argon gas air quenching is used after temperature.

For the corrosion current of 317L-TGT alloy after high temperature quenching treatment under the conditions of logical oxygen, 80 DEG C contain 5 × 10^-6F^-'s The H of 0.5mol/L₂SO₄It is 1.35 μ A/cm in electrolyte².The hardness of alloy is 174HV, yield strength 187MPa, and tension is strong Degree is 594MPa, elongation percentage 41%.

Embodiment 6

Choosing 317L stainless steel waste material, fine copper plate, pure cobalt piece, ferro tantalum, graphite block is raw material, and the stainless composition of steel of configuration is such as Under: C=0.08, Ni=14.2, Cr=19.5, Mo=3.4, Ta=1.20, Cu=0.8, Co=0.3, Mn=1.2, Si= 0.6, P≤0.035, S≤0.030, Fe=surplus.

After weighing good corresponding raw material according to component requirements proportion, through vacuum induction melting, bath temperature is kept when melting 1710℃；Calm 8 minutes of molten steel before being poured, molten steel is at 1580 DEG C, vacuum pouring.

Plate uses flat roll mill hot rolling cogging, and hot rolling scheme is that slab is heated to 1290 DEG C, and heat preservation is come out of the stove after 4.5 hours Rolling, hot rolling start temperature are 1180 DEG C, and finishing temperature is 1050 DEG C.Always lower amount is 80% to plate hot rolling.

Plate uses cold-rolling deformation, and cold rolling overall reduction is 88%.

Plate is made annealing treatment at 1065 DEG C, and soaking time is 85 minutes, cold using nitrogen gas protection and oil.

For the corrosion current of 317L-TGT alloy after high temperature quenching treatment under the conditions of logical oxygen, 80 DEG C contain 5 × 10^-6F^-'s The H of 0.5mol/L₂SO₄It is 1.40 μ A/cm in electrolyte².The hardness of alloy is 178HV, yield strength 197MPa, and tension is strong Degree is 590MPa, elongation percentage 40%.

The performance detection of the preparation process of above-described embodiment 317L-TGT alloy obtained is as described below:

1. pair example alloy material carries out hardness test, load 1Kg, after making a call to 5 points using HVS-50 Vickers It is averaged, is listed in table 1.

2. pair example alloy material carries out stretching experiment using almighty test machine, the nominal section of sample having a size of 1~2 × The rectangular specimen of 5 × 30mm takes the average value of the tensile strength of 3 same treatment samples, yield strength and elongation percentage to be listed in table 1

3. pair example alloy carries out corrosion current measurement, the condition of test are as follows: with corruption using CHI660D electrochemical workstation Erosion face area is 1cm²Example alloy is working electrode, using saturated calomel electrode as reference electrode, using platinized platinum as auxiliary electrode；Contain 5×10^-6F^-0.5mol/L H₂SO₄Electrolyte is heated to 80 DEG C with water bath, and into electrolyte with the flow velocity of 20ml/min It is passed through oxygen；Linear sweep voltametry, sweep speed 2mV/s are carried out to sample.It is averaged after measuring 3 samples, is listed in table 1.

The ingredient and corrosion current, hardness and tensile property of 1 embodiment of table

The ingredients such as Mn, Si, P, S of each embodiment meet alloy invention and require in table 1, and Fe is surplus, is not arranged in table 1 Out.

Claims

1. A high corrosion-resistant stainless steel containing copper, tantalum and cobalt, characterized in that: the mass percentage of each element in the alloy is: C≤0.08, Ni=11.0～15.0, Cr=18.0～20.0, Mo=3.0～4.0, Ta≤1.20 , Cu=0.2～0.8, Co=0.1～0.5, Mn≤2.0, Si≤1.0, P≤0.035, S≤0.030, of which 15.06×(C-0.01)≤Ta≤15.06×C, and the balance is Fe.

2. the processing and heat treatment method of copper-containing tantalum-cobalt high corrosion-resistant stainless steel as claimed in claim 1, is characterized in that comprising the steps:

(1) Smelting and casting of stainless steel

According to the mass percentage of each element required by the alloy, electrical pure iron, metal chrome sheet, metal nickel plate, metal molybdenum, stainless steel scrap, pure copper plate, pure cobalt sheet, tantalum or metal tantalum, and graphite block are selected as raw materials, and arc smelted or After induction melting, cast into alloy ingots;

During smelting, the temperature of the molten pool is kept at 1700℃±20℃; the molten steel is sedated for 5-10 minutes before pouring, and the molten steel is cast at 1550℃±50℃ under vacuum or argon protection, and cast into square ingots or round ingots;

(2) Hot rolling billeting

The plate is hot rolled by a flat roll mill. The hot rolling plan is to heat the slab to 1280°C±10°C, hold it for 3 to 5 hours, and then roll out the furnace. The starting temperature of hot rolling is 1180°C±20°C, and the final rolling temperature is ≥950°C. ℃; the total amount of hot-rolled sheet is ≥ 60%; for pipes, rods, wires, profiles and cold-stamped parts, the ingots can be billed by hot forging, pass rolling or universal rolling;

(3) Cold rolling deformation

The plate is deformed by cold rolling, and the total reduction of cold rolling is ≥80%;

Tubes, bars, wires and profiles are cold-deformed by means of reciprocating tube rolling, pass rolling, universal rolling or drawing to obtain the required size and specification of the product;

(4) High temperature heat treatment

After cold deformation, carry out annealing treatment at 1085℃±30℃, holding time is 30 minutes to 120 minutes, use vacuum or protective gas protection during heating; after annealing, use water, oil or protective gas medium to rapidly cool; corrosion current of alloy Under the condition of oxygen flow, the corrosion rate is 1.08～1.35μA/cm ² in 0.5mol/L H ₂ SO ₄ electrolyte containing 5×10 ^-6 F ^- at 80℃, and the corrosion rate is greatly reduced. The corrosion rate of the stainless steel bipolar plate is comparable; the hardness is 169~178HV1, the yield strength is 187~197MPa, the tensile strength is 587~605MPa, and the elongation rate is 37~42%. It has the characteristics of low hardness and high elongation, which is conducive to bipolar Forming of plate runners.

3. The processing and heat treatment method of copper-tantalum-cobalt high corrosion-resistant stainless steel according to claim 2, wherein the protective gas is argon, nitrogen or helium.

4. the processing and heat treatment method of copper-containing tantalum-cobalt high corrosion-resistant stainless steel as claimed in claim 2, it is characterized in that: the described high temperature heat treatment method of step (4), is to use vacuum heating-air quenching, continuous heating-water cooling Quenching, continuous heating - high pressure gas quenching, gas shielded heating - water quenching or gas shielded heating - oil quenching.

5. The processing and heat treatment method for high corrosion-resistant stainless steel containing copper, tantalum and cobalt as claimed in claim 2, characterized in that: straightening or shaping treatment is performed after annealing, and the deformation amount of the straightening or shaping treatment is less than 2%.