CN108486473B - Low-yield-ratio sulfide stress corrosion resistant 345 MPa-grade steel plate for low-temperature pressure container and preparation method thereof - Google Patents
Low-yield-ratio sulfide stress corrosion resistant 345 MPa-grade steel plate for low-temperature pressure container and preparation method thereof Download PDFInfo
- Publication number
- CN108486473B CN108486473B CN201810457379.7A CN201810457379A CN108486473B CN 108486473 B CN108486473 B CN 108486473B CN 201810457379 A CN201810457379 A CN 201810457379A CN 108486473 B CN108486473 B CN 108486473B
- Authority
- CN
- China
- Prior art keywords
- rolling
- low
- temperature
- equal
- percent
- 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.)
- Active
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
- C21C7/0006—Adding metallic additives
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
- C21C7/0068—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00 by introducing material into a current of streaming metal
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
- C21C7/04—Removing impurities by adding a treating agent
- C21C7/06—Deoxidising, e.g. killing
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
- C21C7/04—Removing impurities by adding a treating agent
- C21C7/072—Treatment with gases
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
- C21C7/10—Handling in a vacuum
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
- C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
- C21D8/0205—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips of ferrous alloys
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
- C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
- C21D8/0221—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the working steps
- C21D8/0226—Hot rolling
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/005—Ferrous alloys, e.g. steel alloys containing rare earths, i.e. Sc, Y, Lanthanides
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/06—Ferrous alloys, e.g. steel alloys containing aluminium
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/08—Ferrous alloys, e.g. steel alloys containing nickel
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/12—Ferrous alloys, e.g. steel alloys containing tungsten, tantalum, molybdenum, vanadium, or niobium
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Mechanical Engineering (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Multimedia (AREA)
- Heat Treatment Of Steel (AREA)
Abstract
The invention discloses a low-yield-ratio sulfide stress corrosion resistant 345 MPa-level steel plate for a low-temperature pressure container, which comprises the following chemical components in percentage by mass: less than or equal to 0.20 percent of C, 0.01 to 0.10 percent of Si, 1.00 to 2.00 percent of MnP, less than or equal to 0.008 percent of P, less than or equal to 0.003 percent of S, less than or equal to 0.01 percent of Nb, less than or equal to 0.035 percent of Alt, less than or equal to 0.01 percent of V, less than or equal to 0.02 percent of RE, 0.10 to 0.50 percent of Ni, and the balance of Fe and inevitable impurities. The invention adopts the component design of low carbon, low silicon and microalloy elements, and combines the TMCP rolling process, the yield ratio of the obtained steel plate is less than or equal to 0.65, the elongation reaches more than 35 percent, the low-temperature impact toughness at minus 40 ℃ reaches more than 150J, and the steel plate has excellent sulfide stress corrosion resistance, weldability and low welding crack sensitivity; and the related preparation process is simple, does not need a heat treatment process, and is suitable for popularization and application.
Description
Technical Field
The invention belongs to the field of pressure vessel steel manufacturing, and particularly relates to a low-yield-ratio sulfide stress corrosion resistant 345 MPa-level steel plate for a low-temperature pressure vessel and a preparation method thereof.
Background
The yield ratio is the ratio of the yield strength to the tensile strength of the steel, and reflects the stress concentration resistance of the steel during plastic deformation. The lower the yield ratio, the higher the uniform elongation of the steel material, and the more safely the steel material can uniformly distribute the plastic deformation over a wide range as a structural member. At present, steel with higher requirement on yield ratio is mainly bridge, building and pipeline steel, the service condition is mostly normal temperature, but with the progressive social progress, the requirement on structural materials is continuously improved, and more strict requirements on yield ratio are provided for steel for low-temperature pressure containers.
The steel for the pressure vessel is widely applied to various aspects of life and production, wherein the steel for the 345 MPa-level low-temperature pressure vessel is generally applied to the fields of storage and transportation of low-temperature liquid such as liquid nitrogen, liquid oxygen, liquid hydrogen, liquid helium, liquefied natural gas and the like, and has wide application range and large market demand; along with the increasing requirements of users on the performance of the steel, the steel for the high-strength pressure container with the low yield ratio, which has higher safety and better processing performance, is more favored by users, and the development of the steel for the low-temperature pressure container with the low yield ratio, 345MPa, which is easy to operate and economical, is particularly important.
Chinese patent 201611152263.X discloses a steel plate for a pressure container with 345 MPa-level yield strength, which mainly comprises the following components: 0.15-0.18% of C, 0.15-0.35% of Si, 1.40-1.50% of Mn, less than or equal to 0.008% of P, less than or equal to 0.002% of S, 0.020-0.040% of Al, 0.020-0.035% of Nb0.003%, and less than or equal to 0.003% of O; the patent mainly realizes low yield ratio and high plasticity by adding a small amount of Nb element and combining with a heat treatment process, but can only meet the performance requirement under the use environment of-10 ℃ (the use environment of a conventional 345 MPa-level pressure container is-40-60 ℃). Chinese patent 200810200100.3 discloses a high strength low yield ratio steel sheet, which mainly comprises: 0.15-0.20% of C, 1.0-2.0% of Si, 1.8-2.0% of Mn, less than or equal to 0.036% of Al, 0.05-0.10% of V, less than or equal to 0.01% of P, less than or equal to 0.005% of S and 0.8-1.0% of Cr0; the patent adopts low alloying treatment and obtains a hot rolled steel plate with high strength and low yield ratio by the traditional TMCP rolling process; but the strength is higher, the low-temperature impact toughness is poorer, and the use environment at lower temperature cannot be met. Chinese patent 201110320517.5 discloses a manufacturing method of a high-toughness steel plate with yield strength of 345-390 MPa, which prepares the high-toughness steel plate with excellent mechanical property through component design and process improvement; however, Ti is added in the steel plate, the yield ratio of the steel plate is not less than 0.70, and the elongation is poor.
Disclosure of Invention
The invention mainly aims to provide a low-yield-ratio sulfide stress corrosion resistant 345 MPa-level steel plate for a low-temperature pressure vessel, aiming at the defects in the prior art; the steel plate for the low-temperature pressure container, which has the advantages of low yield ratio, good low-temperature toughness, sulfide stress corrosion resistance and weldability, is obtained by adopting low-carbon low-silicon and introducing a proper amount of Ni, V, Nb and RE, and combining a TMCP rolling process.
In order to achieve the purpose, the invention adopts the technical scheme that:
the steel plate for the low-temperature pressure vessel with the low yield ratio and the sulfide stress corrosion resistance of 345MPa comprises the following chemical components in percentage by mass: less than or equal to 0.20 percent of C, 0.01 to 0.10 percent of Si, 1.00 to 2.00 percent of Mn, less than or equal to 0.008 percent of P, less than or equal to 0.003 percent of S, less than or equal to 0.01 percent of Nb, less than or equal to 0.035 percent of Alt, less than or equal to 0.01 percent of V, less than or equal to 0.02 percent of RE, 0.10 to 0.50 percent of Ni, and the balance of Fe and inevitable impurities.
The preparation method of the steel plate for the low-temperature pressure vessel with the low yield ratio and the sulfide stress corrosion resistance of 345MPa comprises the steps of blast furnace molten iron, molten iron desulphurization, converter smelting, vacuum treatment, continuous casting, rolling cooling and the like, and specifically comprises the following steps:
1) smelting; the temperature of the incoming molten iron is more than 1250 ℃, and the molten iron is pretreated, and the target value of the sulfur mass fraction of the molten iron is set to be not more than 0.005 percent; adding lime and fine fluorite in the tapping process of the converter to perform tapping pre-refining, and then adopting one-time pre-deoxidation with large aluminum content; after the molten steel enters the LF furnace, argon is blown from the bottom to stir, and the reducing atmosphere in the furnace is kept; the ferromanganese is deoxidized and alloyed, and the addition is started when 1/3 steel is tapped and is finished before 2/3 steel is tapped; tapping temperature is not lower than 1680 ℃, and tapping time is kept at 2.5-6 min; feeding Ca-Si wires in each furnace after the temperature and the components are adjusted, and keeping the soft blowing time to be not less than 10min after the wires are fed; the vacuum treatment time is more than or equal to 15min, rare earth wires are fed into the continuous casting crystallizer, long-nozzle argon sealing casting is adopted during casting, the drawing speed is strictly controlled, weak cooling is adopted in the second cooling section, the casting blank straightening temperature is not lower than 950 ℃, and the surface quality of the continuous casting blank is improved;
2) rolling; the method mainly adopts controlled rolling and controlled cooling technologies, wherein the heating temperature of a plate blank is 1200-1260 ℃, the heating rate is 9-15 min/cm, the rough rolling stage is used for carrying out large-reduction rolling in an austenite recrystallization region, the initial rolling temperature of the rough rolling is 1060-1180 ℃, the first pass reduction rate of the rough rolling is more than 15%, the outlet thickness of a steel plate after the rough rolling is 3.5-10.5 times of the thickness of a finished product, the non-recrystallization region (below 900 ℃) of austenite in a finish rolling stage is used for carrying out multi-pass rolling, the finish rolling temperature is 820-890 ℃, the coiling temperature is 620-710 ℃, the accumulated reduction rate is more than 70%, and the accumulated reduction rate of the last three passes is more than or equal to 30%;
3) cooling after rolling; and (3) adopting a back-end staged laminar cooling mode, wherein the cooling rate is controlled at 8-12 ℃/s: and the temperature of the red returning is 550-670 ℃, and then air cooling is carried out.
The low-yield-ratio sulfide stress corrosion resistance 345 MPa-grade steel plate for the low-temperature pressure container, which is prepared according to the scheme, has the room-temperature yield strength of 345-420 MPa, the tensile strength of 580-675 MPa, the yield ratio of less than or equal to 0.65, the elongation of more than 35 percent, the low-temperature impact toughness of-40 ℃ of more than 150J and the thickness of 4-16 mm, and has excellent sulfide stress corrosion resistance, excellent weldability and low welding crack sensitivity; the use requirements of the low-temperature pressure vessel components are met.
The principle of the invention is as follows:
1) principle of chemical composition design
C, the set range is less than or equal to 0.20 percent, and the optimal range is 0.14-0.18 percent; the carbon element in the steel can fully utilize the strengthening effect of the carbon element, improve the volume fraction of pearlite in the steel and reduce the yield ratio of the steel;
si, the set range is 0.01-0.10%, and the optimal range is 0.01-0.03%; the silicon content in steel (brought from scrap steel and pig iron raw materials during smelting) is increased, although the strength can be improved, the plasticity and the toughness are reduced, the forming property and the welding property of the material are reduced, and the content of silicon element needs to be regulated and controlled;
mn, the set range is 1.00-2.00%, and the optimal range is 1.30-1.60%; good deoxidizer and desulfurizer, which forms solid solution with iron, improves the hardness and strength of ferrite and austenite in steel, can reduce critical transformation temperature, but has little contribution to low-temperature toughness and high-temperature strength of steel, and can increase the overheating sensitivity and temper brittleness tendency of heavy steel when the content of manganese is increased;
nb: the setting range is less than or equal to 0.01 percent, preferably 0.003 to 0.01 percent; niobium produces remarkable fine-grain strengthening and precipitation strengthening effects with medium degree in steel, can form fine carbide and nitride, and inhibits the growth of austenite grains; in the rolling process, the recrystallization temperature can be increased, the recrystallization of austenite is inhibited, the deformation effect is maintained, so that ferrite grains are refined, and the strength and the toughness of the steel are improved;
v: the setting range is less than or equal to 0.01 percent, and preferably 0.002-0.01 percent; vanadium generates weak fine-grain strengthening and obvious precipitation strengthening effects in steel, and simultaneously, when V and Nb are added in a compounding manner, the strength and the toughness of the steel can be improved;
RE: the setting range is less than or equal to 0.02 percent, preferably 0.005-0.02 percent; the addition of a proper amount of rare earth elements into the steel can improve the center segregation of the continuous casting billet and effectively control the form and distribution of inclusions, thereby improving the toughness and the plasticity of the steel plate and improving the cold processing and forming performance of the steel plate; meanwhile, the crack propagation resistance of the steel plate is also obviously improved;
and (3) Alt: the setting range is less than or equal to 0.035%, and preferably 0.015-0.035%; a common deoxidizer in steel fixes free nitrogen in the steel, improves the coarsening temperature of crystal grains of the steel, reduces the brittle transition temperature of the steel, prevents strain and temperature aging, and improves the impact toughness of the steel;
ni: the setting range is 0.1-0.5%, preferably 0.3-0.5%; the steel is an element which can improve the strength and effectively improve the toughness, particularly the low-temperature toughness; the proper Ni content can ensure that the impact energy of the steel reaches more than 150J at the temperature of minus 40 ℃.
P, S and other impurity elements: p, S is a harmful impurity element in steel, P is likely to form segregation in steel to lower the toughness and weldability of steel, and S is likely to form plastic sulfide to make steel have serious anisotropy and deteriorate the impact toughness and workability of steel, although it can greatly improve the strength. Therefore, the content of P, S and other impurity elements in the steel should be strictly controlled.
2) Design principle of production process
The smelting process mainly adopts molten iron desulphurization, adopts high-carbon ferromanganese, ferroniobium and ferrovanadium alloying, and adopts an aluminum wire process, so that the phenomenon of molten steel peroxidation at the end point is reduced, and the content and the grade of oxide inclusions in steel are reduced; feeding rare earth wires into the continuous casting crystallizer, and improving various properties of the steel by utilizing the functions of purifying molten steel and modifying inclusion of rare earth in the steel; naturally cooling the cut casting blank, sending the casting blank to a hot rolling process, and cold charging the steel blank;
the casting blank is subjected to heat preservation and soaking in a heating furnace, the heat preservation time and the tapping temperature are ensured, the head-tail temperature difference of the casting blank is reduced, TMCP is adopted to control rolling in the rolling process, rough rolling is carried out in an austenite recrystallization interval, the rolling pass reduction of the rough rolling is increased, the banded structure can be eliminated or reduced, and the thickness of the intermediate blank is controlled to be 3.5-10.5 times that of the finished product; the finish rolling temperature and the coiling temperature have obvious influence on the strength of the steel, the finish rolling temperature and the coiling temperature are improved, the cooling rate is reduced, and the reduction of the yield ratio is facilitated; and after rolling, a rear-section staged laminar cooling mode is adopted, the rolling cooling rate and the re-reddening temperature are controlled, the nucleation rate of the structure is controlled, the yield strength and the tensile strength are prevented from being improved too high, and the effect of low yield ratio is further realized.
Compared with the prior art, the invention has the beneficial effects that:
the method has the advantages that the low-carbon and low-silicon means is adopted, a small amount of microalloy elements are added, the banded structure in the steel is effectively reduced, the crystal grains are refined, the steel has good strength, low-temperature toughness and lower yield ratio, meanwhile, the conventional steelmaking process is adopted, the low yield ratio effect is further ensured and realized by regulating and controlling the cooling rate of the rolling process, the related preparation process is simple, the heat treatment process is not needed, the process parameters are easy to control, the cost is low, the efficiency is high, and the method is suitable for large-scale production.
Detailed Description
The following examples further illustrate the invention in order that it may be better understood. However, the present invention is not limited to the following examples.
Examples 1 to 6
The chemical compositions of the steel plates for the low-temperature pressure vessel in examples 1 to 6 are respectively shown in Table 1, and the process parameters are respectively shown in Table 2 and Table 3; the preparation method comprises the following steps:
1) smelting; the temperature of the incoming molten iron is more than 1250 ℃, and the molten iron is pretreated, and the target value of the sulfur mass fraction of the molten iron is set to be not more than 0.005 percent; adding small-sized lime and fine fluorite in the tapping process of the converter to perform tapping pre-refining, and then performing one-time large-aluminum-content pre-deoxidation; after the molten steel enters the LF furnace, argon is blown from the bottom to stir, and the reducing atmosphere in the furnace is kept; ferromanganese and ferrosilicon are deoxidized and alloyed, the addition is started when 1/3 steel is tapped, and the addition is finished before 2/3 steel is tapped; tapping temperature is not lower than 1680 ℃, and tapping time is kept at 2.5-6 min; feeding Ca-Si wires in each furnace after the temperature and the components are adjusted, and keeping the soft blowing time to be not less than 10min after the wires are fed; the vacuum treatment time is more than or equal to 15min, rare earth wires are fed into the continuous casting crystallizer, long-nozzle argon sealing casting is adopted during casting, the drawing speed is strictly controlled, weak cooling is adopted in the second cooling section, the casting blank straightening temperature is not lower than 950 ℃, and the surface quality of the continuous casting blank is improved;
2) rolling; the method mainly adopts controlled rolling and controlled cooling technologies, wherein the heating temperature of a plate blank is 1200-1260 ℃, the heating rate is 9-15 min/cm, the rough rolling stage is used for carrying out large-reduction rolling in an austenite recrystallization region, the initial rolling temperature of the rough rolling is 1060-1180 ℃, the first pass reduction rate of the rough rolling is more than 15%, the outlet thickness of a steel plate after the rough rolling is 3.5-10.5 times of the thickness of a finished product, the austenite non-recrystallization region (below 900 ℃) is used for carrying out multi-pass rolling in a finish rolling stage, the finish rolling temperature is 820-890 ℃, the coiling temperature is 620-710 ℃, the accumulated reduction rate is more than 70%, and the accumulated reduction rate of the last pass is more than or equal to 30%;
3) cooling after rolling; adopting a rear-section staged laminar cooling mode, wherein the temperature of the red returning is 550-670 ℃, and then air cooling; respectively obtaining steel products.
TABLE 1 main chemical composition (% by mass) of inventive examples and comparative steels
TABLE 2 Main Process parameters of Steel sheets for Low temperature pressure vessel described in examples 1 to 6 and comparative examples 1 to 2
TABLE 3 results of mechanical Properties test of the steel sheets obtained in examples 1 to 6 and comparative examples 1 to 2
TABLE 4 sulfide stress corrosion resistance test results of the steel sheets obtained in examples 1 to 6 and comparative examples 1 to 2
As can be seen from tables 3 and 4, the invention can completely meet the low-temperature toughness requirement when the environment is-45 ℃, and has good toughness matching, very low yield ratio and good sulfide stress corrosion resistance at room temperature. The steel has good formability and use safety, does not need a heat treatment process, and completely meets the use requirement of a structural part.
It is apparent that the above embodiments are only examples for clearly illustrating and do not limit the embodiments. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. And obvious variations or modifications are therefore intended to be included within the scope of the invention as claimed.
Claims (8)
1. The steel plate for the low-temperature pressure container is characterized by comprising the following chemical components, by mass, 0.14 ~ 0.18.18% of C, 0.01 ~ 0.10.10% of Si, 1.00 ~ 2.00.00% of Mn, less than or equal to 0.008% of P, less than or equal to 0.003% of S, 0.003 ~ 0.01.01% of Nb, less than or equal to 0.035% of Alt, less than or equal to 0.01% of V, less than or equal to 0.02% of RE, 0.10 ~ 0.50.50% of Ni and the balance of Fe and inevitable impurities, wherein the yield ratio of the steel plate is less than or equal to 0.65;
the preparation method comprises smelting, rolling and rolling cooling processes, wherein the cooling rate in the rolling cooling process is 8-12 ℃/s; the smelting process comprises blast furnace molten iron, molten iron desulphurization, converter smelting, vacuum treatment and continuous casting; wherein, Ca-Si wires are fed into each furnace after the temperature and the components are adjusted in the converter smelting process; in the continuous casting process, rare earth wires are fed into a continuous casting crystallizer;
in the rolling process, the heating temperature of a plate blank is 1200 ~ 1260 ℃, the initial rolling temperature of rough rolling is 1060 ~ 1180 ℃, the first pass reduction rate of rough rolling is more than 15 percent, the final rolling temperature of finish rolling is 820 ~ 890 ℃, the coiling temperature is 620 ~ 710 ℃, the cumulative reduction rate of finish rolling is more than 70 percent, and the cumulative reduction rate of the last three passes is more than or equal to 30 percent;
the rolling cooling process adopts a post-stage laminar cooling mode, the temperature of red return is 550 ~ 670 ℃, and then air cooling is carried out.
2. The steel sheet for a low yield ratio sulfide stress corrosion resistance 345MPa grade low temperature pressure vessel as claimed in claim 1, wherein the V content is 0.002 ~ 0.01.01%.
3. The steel sheet for a low yield ratio sulfide stress corrosion resistance 345MPa grade low temperature pressure vessel as claimed in claim 1, wherein the RE content is 0.005 ~ 0.02.02%.
4. The steel sheet for a low yield ratio sulfide stress corrosion resistance 345MPa grade low temperature pressure vessel as claimed in claim 1, wherein the Ni content is 0.3 ~ 0.5.5%.
5. The method for preparing the steel plate for the low-yield-ratio sulfide stress corrosion resistance 345 MPa-level low-temperature pressure container, which is described in any one of claims 1 ~ 4, is characterized by comprising smelting, rolling and rolling cooling processes, wherein the cooling rate in the rolling cooling processes is 8-12 ℃/s.
6. The method of claim 5, wherein the smelting process includes blast furnace molten iron, molten iron desulphurization, converter smelting, vacuum treatment, and continuous casting processes; wherein, Ca-Si wires are fed into each furnace after the temperature and the components are adjusted in the converter smelting process; in the continuous casting process, rare earth wires are fed into a continuous casting crystallizer.
7. The preparation method of claim 5, wherein in the rolling process, the slab heating temperature is 1200 ~ 1260 ℃, the rough rolling start temperature is 1060 ~ 1180 ℃, the rough rolling first pass reduction rate is more than 15%, the finish rolling temperature is 820 ~ 890 ℃, the coiling temperature is 620 ~ 710 ℃, the cumulative reduction rate of finish rolling is more than 70%, and the cumulative reduction rate of the last three passes is more than or equal to 30%.
8. The preparation method of claim 5, wherein the rolling cooling process adopts a post-stage staged laminar cooling mode, the temperature of red returning is 550 ~ 670 and 670 ℃, and then air cooling is carried out.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810457379.7A CN108486473B (en) | 2018-05-14 | 2018-05-14 | Low-yield-ratio sulfide stress corrosion resistant 345 MPa-grade steel plate for low-temperature pressure container and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810457379.7A CN108486473B (en) | 2018-05-14 | 2018-05-14 | Low-yield-ratio sulfide stress corrosion resistant 345 MPa-grade steel plate for low-temperature pressure container and preparation method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN108486473A CN108486473A (en) | 2018-09-04 |
| CN108486473B true CN108486473B (en) | 2020-01-14 |
Family
ID=63352732
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201810457379.7A Active CN108486473B (en) | 2018-05-14 | 2018-05-14 | Low-yield-ratio sulfide stress corrosion resistant 345 MPa-grade steel plate for low-temperature pressure container and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN108486473B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112143955A (en) * | 2020-08-14 | 2020-12-29 | 包头钢铁（集团）有限责任公司 | REMOM method for improving impact toughness of S355ML flange steel |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100833071B1 (en) * | 2006-12-13 | 2008-05-27 | 주식회사 포스코 | Steel plate for pressure vessel with ts 600mpa grade and excellent hic resistance and manufacturing method thereof |
| CN107254633A (en) * | 2017-05-31 | 2017-10-17 | 舞阳钢铁有限责任公司 | Low-temperature pressure container 15MnNiNbDR steel plates and production method |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1148416A (en) * | 1995-02-03 | 1997-04-23 | 新日本制铁株式会社 | High strength line-pipe steel having low-yield ratio and excullent low-temp toughness |
| CN102400040B (en) * | 2010-09-07 | 2014-03-12 | 鞍钢股份有限公司 | Production method of low-carbon bainite steel hot-rolled strip used in low-temperature |
| CN102925798B (en) * | 2012-10-26 | 2014-07-02 | 武汉钢铁(集团)公司 | Steel with yield strength of 450MPa for railway wagon parts and production method |
| CN103849812B (en) * | 2014-03-31 | 2016-08-24 | 武汉钢铁(集团)公司 | Low fragility 700MPa level steel for automobile crossbeam and manufacture method thereof |
| CN107937807B (en) * | 2017-11-18 | 2020-10-02 | 武汉钢铁有限公司 | 770 MPa-grade low-welding-crack-sensitivity pressure vessel steel and manufacturing method thereof |
-
2018
- 2018-05-14 CN CN201810457379.7A patent/CN108486473B/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100833071B1 (en) * | 2006-12-13 | 2008-05-27 | 주식회사 포스코 | Steel plate for pressure vessel with ts 600mpa grade and excellent hic resistance and manufacturing method thereof |
| CN107254633A (en) * | 2017-05-31 | 2017-10-17 | 舞阳钢铁有限责任公司 | Low-temperature pressure container 15MnNiNbDR steel plates and production method |
Also Published As
| Publication number | Publication date |
|---|---|
| CN108486473A (en) | 2018-09-04 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN112048665B (en) | Steel plate for polar region ocean engineering and preparation method thereof | |
| CN110079740B (en) | High-toughness hot-rolled 530 MPa-grade automobile cold-stamped axle housing steel plate and manufacturing method thereof | |
| CN109136738B (en) | High-strength low-temperature-resistant hull structure steel plate and preparation method thereof | |
| CN109536846B (en) | High-toughness hot-rolled steel plate with yield strength of 700MPa and manufacturing method thereof | |
| CN112575257B (en) | Low-cost boron-containing non-quenched and tempered 700MPa high-strength steel and manufacturing method thereof | |
| CN110306111A (en) | A kind of thick steel plates and its manufacturing method | |
| CN112011737B (en) | 390 MPa-grade-20-DEG C-resistant hot-rolled angle steel for bridge structure and production method thereof | |
| CN109385576A (en) | A kind of inexpensive X65 pipe line steel and its manufacturing method based on magnesium processing | |
| CN102605246B (en) | Steel for low-strain-ageing sensitive welding structure and production method of steel | |
| CN110983187A (en) | Novel high-strength weather-resistant pipeline steel X80 steel plate and production method thereof | |
| CN114369764A (en) | High-performance thick hot-rolled H-shaped steel with yield strength of 460MPa and production method thereof | |
| CN112226673A (en) | Hot rolled steel plate with 650 MPa-grade tensile strength and manufacturing method thereof | |
| CN111926253A (en) | Hydrogen sulfide corrosion resistant high-strength toughness normalized steel and manufacturing method thereof | |
| CN102234742A (en) | Steel plate for longitudinal welded pipe and manufacturing method thereof | |
| CN114107822B (en) | 15.9-grade high-strength bolt steel and production method and heat treatment method thereof | |
| CN108588569B (en) | Ocean engineering steel with yield strength of more than or equal to 450MPa and preparation method thereof | |
| WO2020237976A1 (en) | Superfine acicularly-structured structural steel and production method therefor | |
| CN112553524A (en) | Hot rolled steel plate with yield strength of 360MPa for pipeline and manufacturing method thereof | |
| CN110066966B (en) | Low-internal-stress titanium-containing high-strength steel and production method thereof | |
| CN108486473B (en) | Low-yield-ratio sulfide stress corrosion resistant 345 MPa-grade steel plate for low-temperature pressure container and preparation method thereof | |
| CN109930061A (en) | A kind of normalizing type high-strength steel plate and its manufacturing method | |
| CN114480809B (en) | 500 MPa-grade crack arrest steel plate and production method thereof | |
| CN114381652B (en) | Corrosion-resistant steel and steel plate for low-density mobile pressure container and manufacturing method thereof | |
| CN114480958A (en) | Low-cost molybdenum-free non-quenched and tempered 800MPa high-strength steel and manufacturing method thereof | |
| CN114015939A (en) | Anti-seismic steel bar and preparation method thereof |
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 | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |