CN116005071A - X80 crack-arrest steel plate and production method thereof - Google Patents
X80 crack-arrest steel plate and production method thereof Download PDFInfo
- Publication number
- CN116005071A CN116005071A CN202211714200.4A CN202211714200A CN116005071A CN 116005071 A CN116005071 A CN 116005071A CN 202211714200 A CN202211714200 A CN 202211714200A CN 116005071 A CN116005071 A CN 116005071A
- Authority
- CN
- China
- Prior art keywords
- steel
- rolling
- percent
- steel plate
- temperature
- 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
- 229910000831 Steel Inorganic materials 0.000 title claims abstract description 130
- 239000010959 steel Substances 0.000 title claims abstract description 130
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 16
- 238000005096 rolling process Methods 0.000 claims abstract description 71
- 238000001816 cooling Methods 0.000 claims abstract description 22
- 238000010438 heat treatment Methods 0.000 claims abstract description 22
- 238000007670 refining Methods 0.000 claims abstract description 18
- 229910052698 phosphorus Inorganic materials 0.000 claims abstract description 10
- 229910052802 copper Inorganic materials 0.000 claims abstract description 8
- 238000005261 decarburization Methods 0.000 claims abstract description 8
- 229910052759 nickel Inorganic materials 0.000 claims abstract description 8
- 238000003723 Smelting Methods 0.000 claims abstract description 7
- 229910052799 carbon Inorganic materials 0.000 claims abstract description 7
- 229910052742 iron Inorganic materials 0.000 claims abstract description 7
- 239000000126 substance Substances 0.000 claims abstract description 7
- 229910001563 bainite Inorganic materials 0.000 claims abstract description 6
- 238000010521 absorption reaction Methods 0.000 claims abstract description 4
- RMLPZKRPSQVRAB-UHFFFAOYSA-N tris(3-methylphenyl) phosphate Chemical compound CC1=CC=CC(OP(=O)(OC=2C=C(C)C=CC=2)OC=2C=C(C)C=CC=2)=C1 RMLPZKRPSQVRAB-UHFFFAOYSA-N 0.000 claims abstract description 4
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 claims description 32
- 230000009467 reduction Effects 0.000 claims description 19
- 238000000034 method Methods 0.000 claims description 18
- 238000010079 rubber tapping Methods 0.000 claims description 18
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 17
- 230000008569 process Effects 0.000 claims description 17
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 claims description 16
- 229910052786 argon Inorganic materials 0.000 claims description 16
- 238000005266 casting Methods 0.000 claims description 14
- PXHVJJICTQNCMI-UHFFFAOYSA-N nickel Substances [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 claims description 11
- 238000010583 slow cooling Methods 0.000 claims description 11
- 238000007664 blowing Methods 0.000 claims description 10
- 239000002893 slag Substances 0.000 claims description 9
- 238000003756 stirring Methods 0.000 claims description 9
- 229910045601 alloy Inorganic materials 0.000 claims description 7
- 239000000956 alloy Substances 0.000 claims description 7
- 239000010949 copper Substances 0.000 claims description 7
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 6
- 229910052782 aluminium Inorganic materials 0.000 claims description 6
- 239000000203 mixture Substances 0.000 claims description 5
- 238000012360 testing method Methods 0.000 claims description 5
- 235000008733 Citrus aurantifolia Nutrition 0.000 claims description 3
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 3
- 229910001268 Ferrocerium Inorganic materials 0.000 claims description 3
- 229910001309 Ferromolybdenum Inorganic materials 0.000 claims description 3
- 229910000592 Ferroniobium Inorganic materials 0.000 claims description 3
- 229910001200 Ferrotitanium Inorganic materials 0.000 claims description 3
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 claims description 3
- 235000011941 Tilia x europaea Nutrition 0.000 claims description 3
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 claims description 3
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 3
- 239000003245 coal Substances 0.000 claims description 3
- 239000006260 foam Substances 0.000 claims description 3
- ZFGFKQDDQUAJQP-UHFFFAOYSA-N iron niobium Chemical compound [Fe].[Fe].[Nb] ZFGFKQDDQUAJQP-UHFFFAOYSA-N 0.000 claims description 3
- 239000004571 lime Substances 0.000 claims description 3
- 230000001590 oxidative effect Effects 0.000 claims description 3
- 229910052760 oxygen Inorganic materials 0.000 claims description 3
- 239000001301 oxygen Substances 0.000 claims description 3
- 239000002245 particle Substances 0.000 claims description 3
- 239000011574 phosphorus Substances 0.000 claims description 3
- 238000004321 preservation Methods 0.000 claims description 3
- 238000005070 sampling Methods 0.000 claims description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 3
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 2
- 235000013339 cereals Nutrition 0.000 description 10
- 229910052717 sulfur Inorganic materials 0.000 description 5
- 238000003466 welding Methods 0.000 description 5
- 238000004140 cleaning Methods 0.000 description 4
- 238000010586 diagram Methods 0.000 description 4
- 239000000243 solution Substances 0.000 description 4
- 238000009749 continuous casting Methods 0.000 description 3
- 239000013078 crystal Substances 0.000 description 3
- 238000013461 design Methods 0.000 description 3
- 239000012535 impurity Substances 0.000 description 3
- 229910001566 austenite Inorganic materials 0.000 description 2
- 239000011248 coating agent Substances 0.000 description 2
- 238000000576 coating method Methods 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 238000011161 development Methods 0.000 description 2
- 238000006073 displacement reaction Methods 0.000 description 2
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 2
- 230000003647 oxidation Effects 0.000 description 2
- 238000007254 oxidation reaction Methods 0.000 description 2
- 239000002244 precipitate Substances 0.000 description 2
- 238000001556 precipitation Methods 0.000 description 2
- 238000002360 preparation method Methods 0.000 description 2
- 238000003825 pressing Methods 0.000 description 2
- 238000005728 strengthening Methods 0.000 description 2
- 230000007704 transition Effects 0.000 description 2
- 229910052726 zirconium Inorganic materials 0.000 description 2
- 229910000859 α-Fe Inorganic materials 0.000 description 2
- 240000007594 Oryza sativa Species 0.000 description 1
- 235000007164 Oryza sativa Nutrition 0.000 description 1
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 1
- QCWXUUIWCKQGHC-UHFFFAOYSA-N Zirconium Chemical compound [Zr] QCWXUUIWCKQGHC-UHFFFAOYSA-N 0.000 description 1
- 239000008186 active pharmaceutical agent Substances 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 229910052804 chromium Inorganic materials 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 238000007689 inspection Methods 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 229910052748 manganese Inorganic materials 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 229910052750 molybdenum Inorganic materials 0.000 description 1
- 239000003345 natural gas Substances 0.000 description 1
- 229910052758 niobium Inorganic materials 0.000 description 1
- 238000010422 painting Methods 0.000 description 1
- 239000003209 petroleum derivative Substances 0.000 description 1
- 238000004886 process control Methods 0.000 description 1
- 238000010791 quenching Methods 0.000 description 1
- 230000000171 quenching effect Effects 0.000 description 1
- 238000001953 recrystallisation Methods 0.000 description 1
- 235000009566 rice Nutrition 0.000 description 1
- 238000010008 shearing Methods 0.000 description 1
- 239000006104 solid solution Substances 0.000 description 1
- 239000011593 sulfur Substances 0.000 description 1
- 230000009466 transformation Effects 0.000 description 1
- 238000009849 vacuum degassing Methods 0.000 description 1
Images
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/20—Recycling
Abstract
The invention discloses an X80 crack-arrest steel plate and a production method thereof, belonging to the technical field of medium plate production, wherein the thickness of the steel plate is 10 mm-50 mm, and the steel plate comprises the following chemical components in percentage by mass (unit, wt%): c:0.03 to 0.07 percent of Si:0.01% -0.10%, mn:1.90% -2.00%, P: less than or equal to 0.012 percent, S: less than or equal to 0.005 percent, nb:0.060 to 0.070 percent, mo:0.28 to 0.32 percent of Cu:0.35 to 0.39 percent of Ni:0.55% -0.60%, als:0.020% -0.040%, ce:0.002% -0.05%, ti:0.01 to 0.02 percent of Fe and the balance of residual elements, and the production method comprises converter smelting, LF furnace decarburization, LF refining, heating, TMCP rolling and stack cooling. The main structure of the steel plate obtained by the invention is low-carbon bainite, the yield strength is 575-657MPa, the tensile strength is 662-776MPa, the elongation is 19-35%, the impact absorption energy is 166-334J at minus 40 ℃, and the crack arrest temperature is minus 21-35 ℃. Completely meets the performance requirement of the X80 crack-arrest steel plate.
Description
Technical Field
The invention relates to the technical field of medium plate production, in particular to an X80 crack-arrest steel plate and a production method thereof.
Background
X80 belongs to American standard API 5L medium-high strength pipeline steel, and has the characteristics of high strength, excellent low-temperature toughness, good processability and welding performance and the like. With the great increase of petroleum and natural gas demands and the great development of conveying capacity, the quality of pipeline steel is provided with higher requirements, such as weather resistance, service life and the like, the pipeline steel of the current domestic production pipeline is mainly painted on the surface and coated with an anticorrosive coating to improve the weather resistance, the painting and the anticorrosive coating pollute the environment on one hand, the environment is not in line with the environmental protection development requirements at the present stage, and the production cost and the maintenance cost are increased on the other hand. In view of this, the present invention has been made.
The patent with publication number CN108396229B discloses a production method of an X80 pipeline steel wide and thick plate, wherein the thickness of the steel plate is more than or equal to 19mm, and the width is more than or equal to 3800mm. The steel comprises the following chemical components in percentage by mass: c=0.04-0.05%, si is less than or equal to 0.10%, mn=1.20-1.80%, P is less than or equal to 0.015%, S is less than or equal to 0.002%, als=0.02-0.06%, nb=0.02-0.08%, ti=0.010-0.025%, cr is less than or equal to 0.3%, mo is less than or equal to 0.3%, ni is less than or equal to 0.3%, cu is less than or equal to 0.0005%, ca=0.001-0.002%, cr+Mo is less than or equal to 0.3%, cu/Ni is less than or equal to 1.0%, pcm is less than or equal to 0.20%, and the balance is Fe and unavoidable impurities. The steel plate has uniform transverse and longitudinal microstructure, and the transverse and longitudinal full thickness DWTT shearing area at minus 30 ℃ is more than or equal to 85 percent. The production method of the X80 pipeline steel wide and thick plate does not carry out dephosphorization treatment before rolling, and has higher phosphorus content and influences brittle fracture performance.
The patent with publication number CN105088096B discloses X80 pipeline steel with high stress ratio and high crack-arrest toughness, and a preparation method and application thereof, and the pipeline steel consists of the following components in parts by weight: 0.03 to 0.08 percent of C, 0.15 to 0.35 percent of Si, 1.50 to 2.00 percent of Mn, less than or equal to 0.010 percent of P, less than or equal to 0.003 percent of S, 0.04 to 0.08 percent of Nb, 0.015 to 0.025 percent of Ti, 0.015 to 0.025 percent of Zr, less than or equal to 0.03 percent of Mo, less than or equal to 0.35 percent of Cu, less than or equal to 0.30 percent of Ni, less than or equal to 0.30 percent of Cr, and the balance of Fe and unavoidable impurities. According to the invention, by adding zirconium, precipitation of proeutectoid ferrite is promoted, the band structure level is reduced, and the stress ratio and crack-arresting toughness of the steel plate are effectively improved. The preparation method comprises the steps of rough rolling, finish rolling, relaxation and insignificant grain refinement.
Disclosure of Invention
The first object of the present invention is to provide an X80 crack-arrest steel sheet having higher weather resistance and higher low-temperature impact toughness, the X80 crack-arrest steel sheet having a thickness of 10mm to 50mm, comprising the following chemical components in mass percent (unit, wt%): c:0.03 to 0.07 percent of Si:0.01% -0.10%, mn:1.90% -2.00%, P: less than or equal to 0.012 percent, S: less than or equal to 0.005 percent, nb:0.060 to 0.070 percent, mo:0.28 to 0.32 percent of Cu:0.35 to 0.39 percent of Ni:0.55% -0.60%, als:0.020% -0.040%, ce:0.002% -0.05%, ti:0.01 to 0.02 percent, and the balance of Fe and residual elements.
The invention further aims to provide a production method of the X80 crack-arrest steel plate, which adopts an LF refining furnace to realize the decarburization effect equivalent to that of an RH furnace, does not need to additionally increase equipment investment, adopts TMCP rolling and controlled cooling to obtain an ideal steel plate structure, effectively improves the welding performance of the steel plate, and improves the strength and the low-temperature toughness of the steel plate. The production method comprises converter smelting, LF furnace decarburization, LF refining, heating, TMCP rolling and stack cooling, and specifically comprises the following steps:
a. smelting in a converter: decarburizing by adding iron oxide scale into a steel ladle, wherein the tapping temperature of a converter is 1600-1680 ℃, the tapping P is less than or equal to 0.0010%, the tapping C is less than or equal to 0.05%, argon is blown in the whole process of tapping, 300-400kg of iron oxide scale is added into the steel ladle after 1min from tapping, the C content in the steel is reduced by utilizing impact stirring and whole process bottom blowing argon when tapping, 200-400kg of iron oxide scale is continuously added after the molten steel is blown in an argon station for 3min, and then the molten steel is lifted to an LF refining furnace;
and b, decarburizing in an LF furnace: in order to further reduce the carbon content, no deoxidizer is added after the molten steel reaches an LF furnace, the temperature of the molten steel is kept at 1580-1610 ℃ continuously through intermittent heating, strong argon blowing and stirring are carried out for 5-10min, the C element in the steel is continuously removed, the molten steel is uniform in composition, the C content in the steel is lower than 0.03%, and residues on the inner surface of the steel ladle are scraped after decarburization is finished;
LF refining: continuously adding lime and alumina balls into an LF furnace after slagging off to carry out slagging, simultaneously adding aluminum particles to carry out deoxidization, adding 400-800m aluminum wires into molten steel in the slagging process, blowing argon and stirring to remove residual oxygen in the molten steel, starting to add various alloys after slagging off, and carrying out sampling and testing on the alloys, wherein when the content of Als in the steel grade reaches more than 0.025%, firstly adding ferrotitanium, and then adding ferroniobium and ferrocerium after 2min, so that the purposes are that: the high-value alloy is not burnt by oxidation, the high-value alloy plays an effective role, the white slag is kept for 10-25 min, and the final slag after refining is ensured to be foam white slag with good fluidity and proper viscosity;
d. heating: in order to prevent iron scale from being generated, the temperature of a preheating section is less than or equal to 1000 ℃, the temperature of a heating section is 1180-1200 ℃, the temperature of a heat preservation section is 1160-1180 ℃, the overall heating time is 1.3-1.4min/mm, the whole heating process keeps micro positive pressure, the air-coal ratio is 0.8, and the non-oxidizing atmosphere in the furnace is kept;
tmcp rolling: removing phosphorus twice before casting blank rolling, removing iron scales, adopting three-stage rolling, adopting high-temperature, low-speed and large-reduction rolling in the first stage, controlling single-pass reduction to be more than 30mm, achieving deformation that at least 4-pass deformation coefficients are controlled to be more than 0.5, controlling single-pass reduction to be more than 15%, controlling total reduction to be 120-180mm, and rapidly cooling an intermediate blank to 880-900 ℃ in an IC device; when the blank temperature is lower than 900 ℃, starting the second stage rolling, and properly controlling the single-pass rolling reduction to be 10-20mm; when the rolling thickness reaches the final thickness of +5-10mm, relaxation is carried out for 30-60 s, the third stage rolling is started after relaxation, the single pass rolling reduction is 1-3mm, the plate shape is ensured to be flat, and the final rolling temperature is 800-820 ℃; after rolling, the steel plate enters ACC laminar cooling, the cooling speed is more than or equal to 10 ℃/S, and the reddening temperature is 450-550 ℃;
f. and (3) stack cooling: and (3) straightening the steel plate, then placing the steel plate into a slow cooling pit for stacking cooling, wherein the temperature of the stacked steel plate is more than or equal to 200 ℃, the height of the slow cooling stack is controlled to be 2-3 m, and the upper surface and the lower surface of the steel plate are strictly forbidden to be exposed in the air, and the slow cooling time is more than 24 hours.
The twice dephosphorization before casting blank rolling comprises the steps of removing scales by high pressure after the casting blank is discharged from a heating furnace, removing scales, returning to the furnace after the primary descaling is finished, preserving heat for 7-10min, and performing the twice descaling, wherein the descaling water pressure is kept above 20 MPa.
The beneficial effects of the invention are as follows:
the casting blank is subjected to dephosphorization twice before rolling, iron scales are removed, and then three-stage rolling is adopted, wherein the rolling is adopted in the first stage, the rolling is carried out at high temperature, low speed and large rolling, the rolling reduction of single pass is controlled to be more than 30mm, the total rolling reduction is 120-180mm, the deformation of at least 4 passes with the deformation coefficient controlled to be more than 0.5 and the rolling reduction of single pass controlled to be more than 15% is achieved, the grain structure of the center of the steel blank is fully crushed, the maximum meshing of defects such as center micropore looseness is realized, and the internal quality of the steel plate and the grain uniformity in the thickness direction of the steel plate are improved. The rolling force reaches the core of the casting blank, the core of the casting blank is promoted to deform, the pressing of defects such as looseness and the like is promoted, and the total rolling pressure of the steel billet is controlled to be 120-180mm in the rough rolling stage. The shape factor L/H of the deformation zone of the steel plate has a direct relation with the deformation of the rolling pass. Shape factor when deformed
When the rolling force is applied, the rolling force can effectively penetrate into the thickness center of the steel plate, so that rolling deformation is transmitted into the steel plate, and the deformation of the thickness center layer of the steel plate is larger than that of the surface of the steel plate; while when the deformation zone has a shape factor
In the rolling process adopted by the invention, the deformation zone shape coefficient is +.>
At least 3 passes. The intermediate blank enters an IC device to be rapidly cooled to 880-900 ℃.
When the billet temperature is lower than 900 ℃, the second stage rolling is started, the single-pass rolling reduction is properly controlled to be 10-20mm, the rolling force reaches the 1/4 thickness position of the casting billet, the 1/4 position is promoted to deform, and finally the aim of recrystallizing the core part and the 1/4 position is achieved.
When the rolling thickness reaches the final thickness of +5-10mm, relaxation is carried out for 30-60 s, precipitation strengthening of alloy elements is promoted in the rolling cooling process after the deformed austenite is relaxed, a large number of substructures and precipitates exist in deformed grains, new phases are formed on the substructures and the precipitates firstly, the lath length of the deformed austenite is blocked by the boundary of the substructures and early-stage bainite when bainite transformation occurs in the substructures after further cooling, the lath-shaped structure is shorter and finer, and the structure and the grains of the final steel plate are obviously refined; after relaxation, starting a third stage of rolling, wherein the single-pass rolling reduction is 1-3mm, and the finishing rolling temperature is 800-820 ℃ while ensuring the flatness of the plate shape; after rolling, the steel plate enters ACC laminar cooling, the cooling speed is more than or equal to 10 ℃/S, and the reddening temperature is 450-550 ℃.
The main structure of the steel plate obtained according to the scheme is low-carbon bainite, the yield strength is 575-657MPa, the tensile strength is 662-776MPa, the elongation is 19-35%, the impact absorption energy is 166-334J at minus 40 ℃, the crack stop temperature is minus 21-35 ℃, and the performance requirement of the X80 crack stop steel plate is completely met.
Drawings
The present invention will be described in further detail with reference to the accompanying drawings.
FIG. 1 is a diagram showing a metallographic structure of a 30mm thick steel plate of the present invention at a thickness of 1/2 of the head;
FIG. 2 is a metallographic structure diagram of the tail surface of a 30mm thick steel plate according to the invention;
FIG. 3 is a metallographic structure diagram of the tail 1/4 thickness of the 30mm thick steel plate of the invention;
FIG. 4 is a metallographic structure diagram of the tail 1/2 thickness of the 30mm thick steel plate of the invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention are clearly and completely described below with reference to fig. 1 to 4. It will be apparent that the described embodiments are some, but not all, embodiments of the invention. All other embodiments, which are obtained by a person skilled in the art based on the described embodiments of the invention, fall within the scope of protection of the invention.
1. Composition design
C: can improve the hardenability of steel and effectively ensure the tensile strength of the steel plate. However, the increase of the C content can obviously improve the ductile-brittle transition temperature, and the C content strictly sounds the welding performance of the steel plate, so that the C content is controlled to be 0.03-0.07%;
si: the strength of the steel plate is mainly improved by solid solution strengthening in the steel plate, but the strength affects the welding performance and impact performance of the steel plate, so that the low Si design is adopted, and the control is controlled between 0.01 and 0.10 percent;
mn: the quenching degree of the steel plate can be improved, the toughness of the steel plate is not affected, and the Mn content is controlled to be 1.90-2.00%;
p and S: in the steel, P, S is an impurity element, is easy to be biased to a grain boundary, reduces brittle fracture stress, and improves the brittle transition temperature, so that the lower the content is, the better the content is;
al: can play a role in strong deoxidization, refining grains, improving the toughness of steel and controlling the ALs content to be 0.020-0.040%;
nb: the recrystallization temperature of the steel plate can be effectively improved in the controlled rolling process, the growth of crystal grains is prevented, the crystal grains are refined, the strength and toughness of the steel plate are improved, and the Nb content is controlled to be 0.06-0.07%;
mo, namely refining the crystal grains of the steel, improving the hardenability and controlling the content of Mo to be 0.28-0.32%;
ni: the ferrite can be strengthened, and meanwhile, the strength and toughness of the steel are improved, and 0.55% -0.60% of the steel is added in the scheme;
cu: the corrosion resistance of the steel can be improved, and meanwhile, the strength of the steel is improved, and 0.35-0.39% of the steel is added in the scheme;
ce: has the functions of excellent deoxidization, sulfur removal and inclusion improvement, can improve the oxidation resistance and refine grains, and is controlled to be 0.002% -0.05%;
ti: n of the steel grade can be effectively fixed, but the low-temperature impact is not facilitated, and the temperature is controlled to be 0.01% -0.02%;
in summary, the X80 steel plate comprises the following chemical components in percentage by mass (unit, wt%): c:0.03 to 0.07 percent of Si:0.01% -0.10%, mn:1.90% -2.00%, P: less than or equal to 0.012 percent, S: less than or equal to 0.005 percent, nb:0.060 to 0.070 percent, mo:0.28 to 0.32 percent of Cu:0.35 to 0.39 percent of Ni:0.55% -0.60%, als:0.020% -0.040%, ce:0.002% -0.05%, ti:0.01 to 0.02 percent, and the balance of Fe and residual elements.
2. Process control emphasis
2.1 converter smelting process: the tapping temperature of the converter is 1600-1680 ℃, the tapping P is less than or equal to 0.0010%, the tapping C is less than or equal to 0.05%, argon is blown in the whole process of tapping, 300-400kg of iron oxide scale is added into a ladle after 1min from tapping, the C content in the steel is reduced by utilizing impact stirring and whole process of bottom blowing argon when tapping, 200-400kg of iron oxide scale is continuously added after argon is blown into an argon station for 3min from molten steel, and then the molten steel is lifted to an LF refining furnace.
2.2LF process: in the LF refining process, no deoxidizer is added after the molten steel reaches an LF furnace, the temperature of the molten steel is kept at 1580-1610 ℃ continuously through intermittent heating, strong argon blowing and stirring are carried out for 5-10min, and the C element in the steel is continuously removed, so that the component can be uniform, and the C content in the steel is lower than 0.03%; and after decarburization is finished, removing residues on the inner surface of the steel ladle.
After slagging off, continuously adding lime and alumina balls into LF to carry out slagging, simultaneously adding aluminum particles to carry out deoxidization, adding 400-800m aluminum wires into molten steel in the slagging process, blowing argon and stirring to remove residual oxygen in the molten steel, starting to add various alloys after slagging, adding nickel plates, copper plates and ferromolybdenum in the sequence of nickel plates, copper plates and ferromolybdenum, sampling and testing, and adding ferrotitanium after 2min when the Als content of steel grade reaches more than 0.025%, and then adding ferroniobium and ferrocerium and white slag for 10-25 min, so as to ensure that the final slag after refining is foam white slag with good fluidity and proper viscosity.
2.3 vacuum refining process: in the vacuum refining process, the pressure maintaining time is controlled to be less than or equal to 67Pa for 10-20 min, rice hulls are added after vacuum breaking, and then soft blowing is carried out for 3-8 min and then the continuous casting is carried out.
2.4 casting process: in the casting process, the continuous casting drawing speed is constant, the casting superheat degree is controlled according to 5-25 ℃, the billet is piled and cooled for 12-24 hours after casting, and then cleaning and inspection are carried out.
2.5 steel billet cleaning: the temperature is controlled to be 50-400 ℃ by adopting warm cleaning, the cleaning temperature is controlled to be 50-350 ℃ by adopting Wen Zhuanglu after the surface of the billet is cleaned up to be qualified, and the charging temperature is controlled to be 50-350 ℃.
2.6 heating process: in order to prevent iron scale from being generated, the temperature of the preheating section is less than or equal to 1000 ℃, the temperature of the heating section is 1180-1200 ℃, the temperature of the heat preservation section is 1160-1180 ℃, the overall heating time is 1.3-1.4min/mm, the micro positive pressure is kept in the whole heating process, the air-coal ratio is 0.8, and the non-oxidizing atmosphere in the furnace is kept.
2.7 rolling process:
in the rolling process, secondary descaling is adopted before rolling, namely, after a billet is discharged from a heating furnace, scale is removed through high-pressure descaling, after primary descaling, the billet is returned to the furnace and kept for 7-10min, and secondary descaling is carried out, wherein the descaling water pressure is kept above 20 MPa;
adopting a three-stage rolling process, wherein the first stage firstly adopts high-temperature, low-speed and large-reduction rolling, the single-pass reduction is controlled to be more than 30mm, at least 4-pass deformation coefficients are controlled to be more than 0.5, the single-pass reduction rate is controlled to be more than 15%, the total reduction of a billet is controlled to be 120-180mm in the rough rolling stage, and the rough rolling finished intermediate billet enters an IC device for quick cooling to 880-900 ℃; when the blank temperature is lower than 900 ℃, starting the second stage rolling, wherein the single-pass pressing amount is 10-20mm; when the rolling thickness reaches the final thickness of +5-10mm, relaxation is carried out for 30-60 s, the third stage rolling is started after relaxation, the single pass rolling reduction is 1-3mm, the plate shape is ensured to be flat, and the final rolling temperature is 800-820 ℃;
after rolling, the steel plate enters ACC laminar cooling, the cooling speed is more than or equal to 10 ℃/S, and the reddening temperature is 450-550 ℃.
2.8 slow cooling process: and (3) straightening the steel plate, then placing the steel plate into a slow cooling pit for stacking cooling, wherein the temperature of the stacked steel plate is more than or equal to 200 ℃, the height of the slow cooling stack is controlled to be 2-3 m, and the upper surface and the lower surface of the steel plate are strictly forbidden to be exposed in the air, and the slow cooling time is more than 24 hours.
Examples
The X80 crack-arrest steel plate with the thickness of 10mm to 50mm and the chemical composition shown in the following table 1 is obtained through the processes of converter smelting, LF furnace decarburization, LF refining, VD vacuum degassing, continuous casting, billet heating, rolling, slow cooling and the like, and the mechanical properties are shown in the following table 2.
TABLE 1 chemical compositions (Wt,%)
| Thickness (mm) | C | Si | Mn | P | S | Als | Nb | Mo | Ni | Ce | Ti | Cu |
| 12 | 0.03 | 0.03 | 1.92 | 0.006 | 0.002 | 0.028 | 0.065 | 0.29 | 0.58 | 0.019 | 0.011 | 0.37 |
| 20 | 0.05 | 0.05 | 1.98 | 0.008 | 0.001 | 0.034 | 0.063 | 0.30 | 0.57 | 0.038 | 0.016 | 0.35 |
| 30 | 0.04 | 0.04 | 1.93 | 0.009 | 0.003 | 0.039 | 0.067 | 0.31 | 0.59 | 0.031 | 0.015 | 0.38 |
| 50 | 0.05 | 0.07 | 1.97 | 0.007 | 0.002 | 0.026 | 0.062 | 0.29 | 0.56 | 0.027 | 0.019 | 0.37 |
TABLE 2 mechanical properties of 10 mm-50 mm thick X80 crack-arrest steel plates
| Thickness (mm) | Batch number | Yield strength (MPa) | Tensile strength (MPa) | Elongation (%) | Impact energy at-40 ℃ and J |
| 12 | 55 | 593-652 | 684-776 | 20-35 | 197-334 |
| 20 | 60 | 582-650 | 690-760 | 20-29 | 186-329 |
| 30 | 23 | 585-639 | 673-750 | 21-28 | 172-297 |
| 50 | 12 | 575-657 | 662-739 | 19-27 | 166-303 |
The production process is respectively tested for producing 55 batches, 60 batches, 23 batches and 12 batches of X80 steel plates with the thickness of 12mm, 20mm, 30mm and 50mm, the yield strength of the steel plates is 575-657MPa, the tensile strength is 662-776MPa, the elongation is 19-35%, the impact absorption energy is 166-334J at the temperature of minus 40 ℃, and the steel plate structure is a low-carbon bainite structure, so that the design requirement is met.
Crack arrest performance: through ESSO test and NDT test, the crack stop temperature of the steel plate is between minus 21 ℃ and 35 ℃, and the crack stop toughness of brittle cracks is more than 7260N/mm 2/3 Crack tip opening displacement at-10 ℃ is more than 0.63mm, and crack tip opening displacement after welding is more than 0.32mm.
Finally, it is noted that the above-mentioned embodiments are merely for illustrating the technical solution of the present invention, and that other modifications and equivalents thereof by those skilled in the art should be included in the scope of the claims of the present invention without departing from the spirit and scope of the technical solution of the present invention.
Claims (5)
1. An X80 crack-arrest steel plate, characterized in that: comprises the following chemical components in percentage by mass (unit, wt%): c:0.03 to 0.07 percent of Si:0.01% -0.10%, mn:1.90% -2.00%, P: less than or equal to 0.012 percent, S: less than or equal to 0.005 percent, nb:0.060 to 0.070 percent, mo:0.28 to 0.32 percent of Cu:0.35 to 0.39 percent of Ni:0.55% -0.60%, als:0.020% -0.040%, ce:0.002% -0.05%, ti:0.01 to 0.02 percent, and the balance of Fe and residual elements.
2. The X80 crack stop steel sheet of claim 1, wherein: the thickness of the steel plate is 10 mm-50 mm.
3. The X80 crack stop steel sheet according to claim 2, wherein: the main structure of the steel plate is low-carbon bainite, the yield strength is 575-657MPa, the tensile strength is 662-776MPa, the elongation is 19-35%, the impact absorption energy is 166-334J at minus 40 ℃, and the crack arrest temperature is-21-35 ℃.
4. A method for producing an X80 crack-stopper steel sheet according to claim 3, characterized in that: the method comprises converter smelting, LF furnace decarburization, LF refining, heating, TMCP rolling and stack cooling, and specifically comprises the following steps:
a. smelting in a converter: decarburizing by adding iron oxide scale into a steel ladle, wherein the tapping temperature of a converter is 1600-1680 ℃, the tapping P is less than or equal to 0.0010%, the tapping C is less than or equal to 0.05%, argon is blown in the whole process of tapping, 300-400kg of iron oxide scale is added into the steel ladle after 1min from tapping, the C content in the steel is reduced by utilizing impact stirring and whole process bottom blowing argon when tapping, 200-400kg of iron oxide scale is continuously added after the molten steel is blown in an argon station for 3min, and then the molten steel is lifted to an LF refining furnace;
and b, decarburizing in an LF furnace: in order to further reduce the carbon content, no deoxidizer is added after the molten steel reaches an LF furnace, the temperature of the molten steel is kept at 1580-1610 ℃ continuously through intermittent heating, strong argon blowing and stirring are carried out for 5-10min, the C element in the steel is continuously removed, the molten steel is uniform in composition, the C content in the steel is lower than 0.03%, and residues on the inner surface of the steel ladle are scraped after decarburization is finished;
LF refining: continuously adding lime and alumina balls into an LF furnace for slagging after slagging, simultaneously adding aluminum particles for deoxidization, adding 400-800m aluminum wires into molten steel in the slagging process, blowing argon and stirring to remove residual oxygen in the molten steel, starting to add various alloys after slagging, and adding nickel plates, copper plates and ferromolybdenum in the sequence of sampling and testing, wherein ferrotitanium is firstly added after 2min when the Als content of steel grade reaches more than 0.025%, and then ferroniobium and ferrocerium are added, wherein the white slag is kept for 10-25 min, so that the finished slag after refining is foam white slag with good fluidity and proper viscosity;
d. heating: in order to prevent iron scale from being generated, the temperature of a preheating section is less than or equal to 1000 ℃, the temperature of a heating section is 1180-1200 ℃, the temperature of a heat preservation section is 1160-1180 ℃, the overall heating time is 1.3-1.4min/mm, the whole heating process keeps micro positive pressure, the air-coal ratio is 0.8, and the non-oxidizing atmosphere in the furnace is kept;
tmcp rolling: removing phosphorus twice before casting blank rolling, removing iron scales, adopting three-stage rolling, adopting high-temperature, low-speed and large-reduction rolling in the first stage, controlling single-pass reduction to be more than 30mm, achieving deformation that at least 4-pass deformation coefficients are controlled to be more than 0.5, controlling single-pass reduction to be more than 15%, controlling total reduction to be 120-180mm, and rapidly cooling an intermediate blank to 880-900 ℃ in an IC device; when the blank temperature is lower than 900 ℃, starting the second stage rolling, and properly controlling the single-pass rolling reduction to be 10-20mm; when the rolling thickness reaches the final thickness of +5-10mm, relaxation is carried out for 30-60 s, the third stage rolling is started after relaxation, the single pass rolling reduction is 1-3mm, the plate shape is ensured to be flat, and the final rolling temperature is 800-820 ℃; after rolling, the steel plate enters ACC laminar cooling, the cooling speed is more than or equal to 10 ℃/S, and the reddening temperature is 450-550 ℃;
f. and (3) stack cooling: and (3) straightening the steel plate, then placing the steel plate into a slow cooling pit for stacking cooling, wherein the temperature of the stacked steel plate is more than or equal to 200 ℃, the height of the slow cooling stack is controlled to be 2-3 m, and the upper surface and the lower surface of the steel plate are strictly forbidden to be exposed in the air, and the slow cooling time is more than 24 hours.
5. The method for producing an X80 crack-arrest steel sheet according to claim 4, wherein: the twice dephosphorization before casting blank rolling comprises the steps of removing scales by high pressure after the casting blank is discharged from a heating furnace, removing scales, returning to the furnace after the primary descaling is finished, preserving heat for 7-10min, and performing the twice descaling, wherein the descaling water pressure is kept above 20 MPa.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211714200.4A CN116005071A (en) | 2022-12-27 | 2022-12-27 | X80 crack-arrest steel plate and production method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211714200.4A CN116005071A (en) | 2022-12-27 | 2022-12-27 | X80 crack-arrest steel plate and production method thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN116005071A true CN116005071A (en) | 2023-04-25 |
Family
ID=86029407
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211714200.4A Pending CN116005071A (en) | 2022-12-27 | 2022-12-27 | X80 crack-arrest steel plate and production method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN116005071A (en) |
Citations (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101205593A (en) * | 2007-12-10 | 2008-06-25 | 华北石油管理局第一机械厂 | X80 steel bend pipe and bending technique thereof |
| CN101205594A (en) * | 2007-12-10 | 2008-06-25 | 华北石油管理局第一机械厂 | X80 steel made pipe fittings and manufacture technique thereof |
| CN101341269A (en) * | 2006-04-13 | 2009-01-07 | 新日本制铁株式会社 | High-strength steel plate with superior crack arrestability |
| CN101845596A (en) * | 2009-03-24 | 2010-09-29 | 宝山钢铁股份有限公司 | Wide thick plate for X80 pipe line steel and manufacturing method thereof |
| CN101868560A (en) * | 2007-11-22 | 2010-10-20 | Posco公司 | High strength and low yield ratio steel for structure having excellent low temperature toughness |
| CN102242323A (en) * | 2011-08-25 | 2011-11-16 | 中国石油集团渤海石油装备制造有限公司 | X80 steel, low-temperature-resistant pipe fitting manufactured from X80 steel and manufacturing method of pipe fitting |
| CN102268612A (en) * | 2011-08-25 | 2011-12-07 | 中国石油集团渤海石油装备制造有限公司 | X80 steel elbow with low temperature resistance and manufacturing process thereof |
| CN102851587A (en) * | 2012-09-06 | 2013-01-02 | 江苏沙钢集团有限公司 | Anti-deformation X80-X100 pipeline steel plate and manufacturing method thereof |
| CN103695807A (en) * | 2013-12-13 | 2014-04-02 | 莱芜钢铁集团有限公司 | Ultrahigh-strength X100 pipeline steel plate with excellent crack resistance and preparation method thereof |
| CN104561831A (en) * | 2015-01-30 | 2015-04-29 | 宝山钢铁股份有限公司 | Steel plate with high anti-crack property and manufacturing method of steel plate |
| CN105088096A (en) * | 2015-08-31 | 2015-11-25 | 山东钢铁股份有限公司 | X80 pipeline steel with high stress ratio and high arrest toughness and preparation method and application of X80 pipeline steel |
| CN106834932A (en) * | 2016-12-05 | 2017-06-13 | 马鞍山钢铁股份有限公司 | A kind of low-carbon (LC) X80 pipe line steels coiled sheet and its manufacture method |
| CN110983187A (en) * | 2019-12-25 | 2020-04-10 | 南阳汉冶特钢有限公司 | Novel high-strength weather-resistant pipeline steel X80 steel plate and production method thereof |
| CN111961957A (en) * | 2020-06-29 | 2020-11-20 | 江阴兴澄特种钢铁有限公司 | X80-grade pipeline steel plate with seawater corrosion resistance and large deformation resistance and manufacturing method thereof |
| CN114395731A (en) * | 2021-12-16 | 2022-04-26 | 南阳汉冶特钢有限公司 | Low-welding crack sensitivity crack arrest steel HY950CF for hydroelectric engineering and production method thereof |
-
2022
- 2022-12-27 CN CN202211714200.4A patent/CN116005071A/en active Pending
Patent Citations (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101341269A (en) * | 2006-04-13 | 2009-01-07 | 新日本制铁株式会社 | High-strength steel plate with superior crack arrestability |
| CN101868560A (en) * | 2007-11-22 | 2010-10-20 | Posco公司 | High strength and low yield ratio steel for structure having excellent low temperature toughness |
| CN101205593A (en) * | 2007-12-10 | 2008-06-25 | 华北石油管理局第一机械厂 | X80 steel bend pipe and bending technique thereof |
| CN101205594A (en) * | 2007-12-10 | 2008-06-25 | 华北石油管理局第一机械厂 | X80 steel made pipe fittings and manufacture technique thereof |
| CN101845596A (en) * | 2009-03-24 | 2010-09-29 | 宝山钢铁股份有限公司 | Wide thick plate for X80 pipe line steel and manufacturing method thereof |
| CN102268612A (en) * | 2011-08-25 | 2011-12-07 | 中国石油集团渤海石油装备制造有限公司 | X80 steel elbow with low temperature resistance and manufacturing process thereof |
| CN102242323A (en) * | 2011-08-25 | 2011-11-16 | 中国石油集团渤海石油装备制造有限公司 | X80 steel, low-temperature-resistant pipe fitting manufactured from X80 steel and manufacturing method of pipe fitting |
| CN102851587A (en) * | 2012-09-06 | 2013-01-02 | 江苏沙钢集团有限公司 | Anti-deformation X80-X100 pipeline steel plate and manufacturing method thereof |
| CN103695807A (en) * | 2013-12-13 | 2014-04-02 | 莱芜钢铁集团有限公司 | Ultrahigh-strength X100 pipeline steel plate with excellent crack resistance and preparation method thereof |
| CN104561831A (en) * | 2015-01-30 | 2015-04-29 | 宝山钢铁股份有限公司 | Steel plate with high anti-crack property and manufacturing method of steel plate |
| CN105088096A (en) * | 2015-08-31 | 2015-11-25 | 山东钢铁股份有限公司 | X80 pipeline steel with high stress ratio and high arrest toughness and preparation method and application of X80 pipeline steel |
| CN106834932A (en) * | 2016-12-05 | 2017-06-13 | 马鞍山钢铁股份有限公司 | A kind of low-carbon (LC) X80 pipe line steels coiled sheet and its manufacture method |
| CN110983187A (en) * | 2019-12-25 | 2020-04-10 | 南阳汉冶特钢有限公司 | Novel high-strength weather-resistant pipeline steel X80 steel plate and production method thereof |
| CN111961957A (en) * | 2020-06-29 | 2020-11-20 | 江阴兴澄特种钢铁有限公司 | X80-grade pipeline steel plate with seawater corrosion resistance and large deformation resistance and manufacturing method thereof |
| CN114395731A (en) * | 2021-12-16 | 2022-04-26 | 南阳汉冶特钢有限公司 | Low-welding crack sensitivity crack arrest steel HY950CF for hydroelectric engineering and production method thereof |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111363973B (en) | Super-thick container steel plate with excellent core low-temperature impact toughness and manufacturing method thereof | |
| CN110295320B (en) | Large-wall-thickness X52MS acid-resistant pipeline steel plate produced by LF-RH refining process and manufacturing method thereof | |
| WO2021196820A1 (en) | Method for manufacturing low remanence 5ni steel plate with excellent surface quality | |
| CN111441000A (en) | 690 MPa-yield-strength low-yield-ratio high-strength steel plate and manufacturing method thereof | |
| CN109112423B (en) | Super-thick alloy steel plate with excellent low-temperature toughness and preparation method thereof | |
| CN109628828B (en) | Low-yield-ratio ultra-thick hydroelectric high-strength steel plate and manufacturing method thereof | |
| CN107974612B (en) | High-strength and high-toughness steel plate for SSCC (single strand ceramic) resistant spherical tank and manufacturing method thereof | |
| CN109338215B (en) | High-strength steel plate with thickness of 8-25 mm and low yield ratio for tank car and manufacturing method thereof | |
| CN114134406B (en) | Spherical tank steel plate with thickness of 20-50mm and excellent low-temperature toughness of core and manufacturing method thereof | |
| CN110735085A (en) | Manufacturing method of thin Q345qE and Q370qE steel plates | |
| CN112877599B (en) | Ultrahigh-strength quenched and tempered marine steel plate with excellent low-temperature performance and manufacturing method thereof | |
| WO2022022040A1 (en) | Low temperature-resistant hot-rolled h-type steel for 355mpa marine engineering and preparation method therefor | |
| CN115181911B (en) | Super-thick Q500qE bridge steel plate and production method thereof | |
| WO2023173803A1 (en) | Rolling contact fatigue resistant steel rail for mixed passenger and freight railway, and production method therefor | |
| CN114480975B (en) | Economical X65-grade acid-resistant pipeline steel plate coil and manufacturing method thereof | |
| CN110184530B (en) | Normalized steel sheet for pipe used under low temperature and acidic conditions and method for producing same | |
| CN111926252B (en) | Hot-rolled pickled steel plate for deep drawing and production method thereof | |
| CN111270169A (en) | Ni-containing alloy steel plate with excellent low-temperature toughness and production method thereof | |
| CN107541663B (en) | A kind of beverage can ferrostan and its production method | |
| CN115786812B (en) | 9Ni steel plate for large-thickness low-yield-ratio LNG storage tank and production method thereof | |
| CN111763880A (en) | Low-yield-ratio ultra-thick hydroelectric high-strength steel plate and manufacturing method thereof | |
| CN111996462A (en) | Longitudinal variable-thickness ultrahigh-strength ship board and production method thereof | |
| CN115261746B (en) | Super-thick Q420qE bridge steel plate and production method thereof | |
| CN111020349A (en) | Manufacturing method of 150-doped 200 mm-thick normalized easy-to-weld hydroelectric steel plate | |
| CN110629002A (en) | Method for producing low-compression-ratio lamellar tearing-resistant extra-thick plate based on TMCP (thermal mechanical control processing) |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |