CN110791712A - SA738GrB steel plate for nuclear power station containment vessel and manufacturing method - Google Patents
SA738GrB steel plate for nuclear power station containment vessel and manufacturing method Download PDFInfo
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- G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
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Abstract
The invention discloses a SA738GrB steel plate for a nuclear power station containment vessel, which relates to the technical field of steel smelting, and comprises the following chemical components in percentage by mass, wherein the thickness specification is 101mm, the width specification is 4650 mm: c is less than or equal to 0.2%, Si: 0.13-0.6%, Mn: 0.9 to 1.6 percent of Ni, less than or equal to 0.6 percent of Cr, less than or equal to 0.3 percent of Nb, less than or equal to 0.05 percent of Mo, less than or equal to 0.35 percent of V, less than or equal to 0.03 percent of Ti, and the balance of Fe and inevitable impurities. The thickness of the finished product is 101mm, and the width of the finished product reaches 4650mm, so that the finished product has the advantages of good obdurability, weldability and the like, and meets the use requirements of the containment vessel of the nuclear power station.
Description
Technical Field
The invention relates to the technical field of steel smelting, in particular to a SA738GrB steel plate for a nuclear power station containment vessel and a manufacturing method thereof.
Background
Nuclear energy is currently recognized as a clean, efficient and safe source of energy. According to the prediction of international authorities, 90-300 reactors of 1600 megawatts are built globally by 2038 years, and the development of nuclear power enters a rapid rise period. The nuclear power construction in China starts in the middle of the eighties of the last century, the development is rapid, and by 2017, 37 nuclear power generating units are operated in continental regions, 19 nuclear power generating units are operated in a building, and the number of the nuclear power generating units under construction is the first in the world. By 2020, the nuclear power operation and the building installation in China can reach 8800 ten thousand kilowatts, and the installed capacity of the nuclear power accounts for more than 5 percent of the total installed capacity of the domestic power.
The containment vessel is used as a protection device of nuclear island equipment, is an important component of a pressurized water reactor nuclear power station, and is a last safety barrier for preventing radioactive substances from leaking. At present, the main nuclear reactor type in China is an AP1000 nuclear reactor type designed by West House company, the main material of a steel containment vessel is an SA738 Gr.B steel plate, the thickness specification of the steel is high, the requirement on technical indexes is strict, and the performance control is difficult. With the international improvement of the safety requirement of the nuclear power station, the performance requirement of the steel containment steel plate is higher and higher, and the welding seam length of the assembly is reduced as much as possible from the perspective of the safety of the nuclear containment, so that one of the development directions of the nuclear containment is integration and integration, the thickness and the width are improved on the basis of ensuring the performance, and great difficulty is brought.
The ultra-wide and ultra-thick steel plate has large thickness and large width at the same time, so that the utilization rate of the steel plate is higher than that of steel plates with other sizes when the containment vessel of the nuclear power station is manufactured, the welding workload can be saved, and the safety of the containment vessel can be improved. At present, the invention patents related to the steel grade can not reach the thickness of 101mm and the width of 4650mm at the same time, such as:
CN201811165254.3 discloses a steel for extra-wide and extra-thick nuclear power conventional island equipment and a manufacturing method thereof, wherein the steel contains C: 0.10% -0.18%, Si: 0.15-0.40%, Mn: 0.90-1.50%, P is less than or equal to 0.02%, S is less than or equal to 0.005%, Ni: 0.10-0.30%, Cr: 0.15% -0.30%, V: 0.01 to 0.05 percent, Nb: 0.01-0.05%, Als: 0.015 to 0.04 percent, and the balance of iron and inevitable impurities. Heating the continuous casting blank at 1200-1250 ℃ for 4-6 h; the initial rolling temperature of the first stage is more than or equal to 1100 ℃, and the total rolling reduction rate is more than or equal to 60%; in the second stage, the initial rolling temperature is 900-950 ℃, and the final rolling temperature is 800-850 ℃; normalizing at 880-920 ℃, keeping the temperature for 1-3 min/mm, and naturally cooling after discharging. The thickness of the finished steel plate is 60-100 mm, the width is 4000-5100 mm, and the using conditions of the steel for the conventional island equipment of the nuclear power station are met. The width of the steel plate reaches the highest value of the current industry, but the maximum width of the steel plate with the thickness of 100mm can only reach 4200mm, and the strength of the steel plate after normalizing is low.
CN201510302071.1 discloses a large-thickness SA738GrA steel plate and a production method thereof, which are composed of the following components by weight percentage: c: 0.14% -0.16%, Si: 0.25-0.45%, Mn: 1.35-1.45%, P is less than or equal to 0.020%, S is less than or equal to 0.010%, Cr: 0.15-0.20%, Mo is less than or equal to 0.06%, Ti is less than or equal to 0.02%, Ni: 0.20-0.30%, Cu is less than or equal to 0.05%, Al: 0.020-0.050%, V less than or equal to 0.07%, Nb less than or equal to 0.04%, Nb + V less than or equal to 0.07%, and the balance of Fe and inevitable impurities. The steel plate optimizes the element components and the proportion in the steel plate, so that the thickness of the SA738GrA steel plate reaches 112mm, the obtained steel plate meets the B-grade requirement in the ASME SA578/SA578M flaw detection standard, but the width of the steel plate is unknown, the yield strength is only about 310MPa, the low-temperature toughness is poor, and the impact energy at-46 ℃ is about 27 joules.
CN201610058164.9 discloses a large-thickness SA738GrB steel plate for nuclear island equipment and a production method thereof, wherein the steel plate comprises the following components in percentage by weight: c: 0.05-0.20%, Si: 0.15-0.55%, Mn: 0.90% -1.60%, P is less than or equal to 0.009%, S is less than or equal to 0.006%, Cr is less than or equal to 0.30%, Mo is less than or equal to 0.30%, Cu is less than or equal to 0.35%, Ni is less than or equal to 0.60%, V is less than or equal to 0.07%, Nb is less than or equal to 0.04%, Ti is less than or equal to 0.03%, and the balance of Fe and inevitable impurities. The steel plate is modified by adopting a quenching and tempering heat treatment process, and the micro-alloy elements form composite reinforcement, so that good toughness and toughness matching is obtained. The thickness of the steel sheet can be up to 130mm, but there is no data on the width.
Disclosure of Invention
In order to solve the technical problems, the invention provides a SA738GrB steel plate for a nuclear power station containment, which has the thickness specification of 101mm and the width specification of 4650mm, and comprises the following chemical components in percentage by mass: c is less than or equal to 0.2%, Si: 0.13-0.6%, Mn: 0.9 to 1.6 percent of Ni, less than or equal to 0.6 percent of Cr, less than or equal to 0.3 percent of Nb, less than or equal to 0.05 percent of Mo, less than or equal to 0.35 percent of V, less than or equal to 0.03 percent of Ti, and the balance of Fe and inevitable impurities.
The technical effects are as follows: the thickness of the steel plate finished product designed by the invention is 101mm, and the width of the steel plate finished product reaches 4650mm, so that the steel plate has the advantages of good obdurability, weldability and the like, and meets the use requirements of the containment vessel of the nuclear power station.
The technical scheme of the invention is further defined as follows:
the SA738GrB steel plate for the nuclear power station containment comprises the following chemical components in percentage by mass: c: 0.15%, Mn: 1.53%, P: 0.009%, S: 0.001%, Si: 0.25%, Ni: 0.54%, Cr: 0.022%, Nb: 0.03%, Mo: 0.17%, V: 0.044%, Ti: 0.016%, Alt: 0.04%, and the balance of Fe and inevitable impurities.
The SA738GrB steel plate for the nuclear power station containment comprises the following chemical components in percentage by mass: c: 0.14%, Mn: 1.55%, P: 0.008%, S: 0.001%, Si: 0.25%, Ni: 0.55%, Cr: 0.25%, Nb: 0.03%, Mo: 0.28%, V: 0.044%, Ti: 0.017%, Alt: 0.02%, and the balance of Fe and inevitable impurities.
The SA738GrB steel plate for the nuclear power station containment comprises the following chemical components in percentage by mass: c: 0.13%, Mn: 1.55%, P: 0.009%, S: 0.001%, Si: 0.25%, Ni: 0.56%, Cr: 0.23%, Nb: 0.03%, Mo: 0.27%, V: 0.045%, Ti: 0.016%, Alt: 0.05%, and the balance of Fe and inevitable impurities.
Another object of the present invention is to provide a method for manufacturing a SA738GrB steel plate for a nuclear power plant containment vessel, including the steps of: the method comprises the following steps of molten steel pretreatment, converter smelting, refining, continuous casting, heating, rolling and heat treatment, and is characterized in that:
molten iron desulphurization pretreatment: the starting temperature is 1330-1370 ℃, the ending temperature is 1320-1350 ℃, 0.3-1.0 kg/ton magnesium powder and 2.5-4.0 kg/ton lime powder are sprayed, and S is less than or equal to 0.005 percent after the ending;
smelting and refining the molten steel, then carrying out continuous casting, wherein the superheat degree of the molten steel is 5-25 ℃, the throwing speed is 0.55-0.75 m/min, and carrying out continuous casting secondary cooling electromagnetic stirring: current 200-450A, frequency 5-7 Hz, light pressure: the reduction interval is 50-95%, the reduction is 4-8 mm, and the thickness of the continuous casting billet is 320 mm;
heating temperature of the continuous casting billet is 1180-1250 ℃, furnace time is 4.8-7.0 h, after the billet is discharged from a furnace and descaled, firstly, transverse rolling is carried out until the width of a finished product is wide, then longitudinal rolling is carried out, and rolling is carried out in two stages: the rolling temperature of the first stage is 1000-1150 ℃, and the accumulated reduction is 50-70%; in the second stage, the initial rolling thickness is 184mm, the accumulated reduction is 40-60%, and the rolled steel plate is cooled in air;
quenching: heating the steel plate in a quenching furnace, wherein the heating heat preservation temperature is 890-930 ℃, and the total heat preservation time is 2.1 min/mm; carrying out laminar cooling on the steel plate in a roller type quenching machine after heat preservation, wherein the laminar cooling process comprises a high-pressure section and a low-pressure section, the laminar pressure of the high-pressure section is 0.8MPa, the water-feeding-water ratio is 0.85, the laminar pressure of the low-pressure section is 0.5MPa, the water-feeding-water ratio is 0.88, and the roll gap of a roller of the quenching machine is set to be 101 mm; after the high-pressure section is cooled, the steel plate swings for more than 18min in the low-pressure section, and the integral temperature of the cooled steel plate is ensured to be below 100 ℃;
tempering: and (3) heating the steel plate in a tempering furnace to the tempering temperature of 660-680 ℃, preserving heat for more than 2.5min/mm, taking out of the furnace after heat preservation, and air cooling.
The invention has the beneficial effects that:
(1) the thickness specification of the steel plate reaches 101mm, the width specification of the steel plate reaches 4650mm, the length of a welding line of the assembly can be effectively reduced from the perspective of safety of the nuclear containment, integration and integration of the containment are further realized, the utilization rate of the steel plate is high, and the safety is good;
(2) the invention solves the problem of lower low-temperature impact toughness of the nuclear power steel ultra-wide and ultra-thick plate by adopting high-cleanliness smelting, low-segregation continuous casting, two-stage controlled rolling and off-line roller type high-strength high-uniformity quenching and tempering heat treatment, and the steelThe plate has good obdurability matching, and the mechanical property of the steel plate obtained by the method of the invention at the delivery state thickness 1/4 is detected as follows: rP0.2≥635MPa,Rm≥710MPa,A5d≥20%,-25℃Kv8(average value) 84J or more and-35 ℃ Kv8(average value) is more than or equal to 52J; performance of the simulated postweld heat treatment: rp0.2≥615MPa,Rm≥710MPa,A5dNot less than 21%, and-35 ℃ transverse KV8The average value of the impact work is more than or equal to 75J;
(3) compared with the common controlled rolling and heat treatment steel plate, the invention improves the comprehensive performance of the steel plate by the design of the same chemical components, the obtained steel plate has good obdurability, especially greatly improves the low-temperature impact toughness, and reduces the production resource consumption of the steel plate.
Drawings
FIG. 1 is an SEM image of a steel sheet obtained in example 1 of the present invention.
Detailed Description
A SA738GrB steel plate for a nuclear power station containment vessel has a thickness specification of 101mm and a width specification of 4650mm, and comprises the following chemical components in percentage by mass: c is less than or equal to 0.2%, Si: 0.13-0.6%, Mn: 0.9 to 1.6 percent of Ni, less than or equal to 0.6 percent of Cr, less than or equal to 0.3 percent of Nb, less than or equal to 0.05 percent of Mo, less than or equal to 0.35 percent of V, less than or equal to 0.03 percent of Ti, and the balance of Fe and inevitable impurities.
The method for manufacturing the steel sheet includes the following steps: molten steel pretreatment, converter smelting, refining, continuous casting, heating, rolling and heat treatment,
molten iron desulphurization pretreatment: the starting temperature is 1330-1370 ℃, the ending temperature is 1320-1350 ℃, 0.3-1.0 kg/ton magnesium powder and 2.5-4.0 kg/ton lime powder are sprayed, and S is less than or equal to 0.005 percent after the ending;
smelting and refining the molten steel, then carrying out continuous casting, wherein the superheat degree of the molten steel is 5-25 ℃, the throwing speed is 0.55-0.75 m/min, and carrying out continuous casting secondary cooling electromagnetic stirring: current 200-450A, frequency 5-7 Hz, light pressure: the reduction interval is 50-95%, the reduction is 4-8 mm, and the thickness of the continuous casting billet is 320 mm;
heating temperature of the continuous casting billet is 1180-1250 ℃, furnace time is 4.8-7.0 h, after the billet is discharged from a furnace and descaled, firstly, transverse rolling is carried out until the width of a finished product is wide, then longitudinal rolling is carried out, and rolling is carried out in two stages: the rolling temperature of the first stage is 1000-1150 ℃, and the accumulated reduction is 50-70%; in the second stage, the initial rolling thickness is 184mm, the accumulated reduction is 40-60%, and the rolled steel plate is cooled in air;
quenching: heating the steel plate in a quenching furnace, wherein the heating heat preservation temperature is 890-930 ℃, and the total heat preservation time is 2.1 min/mm; carrying out laminar cooling on the steel plate in a roller type quenching machine after heat preservation, wherein the laminar cooling process comprises a high-pressure section and a low-pressure section, the laminar pressure of the high-pressure section is 0.8MPa, the water-feeding-water ratio is 0.85, the laminar pressure of the low-pressure section is 0.5MPa, the water-feeding-water ratio is 0.88, and the roll gap of a roller of the quenching machine is set to be 101 mm; after the high-pressure section is cooled, the steel plate swings for more than 18min in the low-pressure section, and the integral temperature of the cooled steel plate is ensured to be below 100 ℃;
tempering: and (3) heating the steel plate in a tempering furnace to the tempering temperature of 660-680 ℃, preserving heat for more than 2.5min/mm, taking out of the furnace after heat preservation, and air cooling.
The technical solution of the present invention is further illustrated below with reference to examples 1 to 3.
TABLE 1 examples Steel smelting chemistries (wt,%)
A heating rolling procedure: heating temperature of the continuous casting blank is 1180-1250 ℃, furnace time is 4.8-7.0 hours, and after steel billets are discharged and descaled, the steel billets are firstly rolled transversely to the width of finished products and then rolled longitudinally. Rolling in two stages: the first stage rolling temperature is 1050 ℃, and the accumulated reduction is 55%; the second stage is started to roll with the thickness of 184mm, and the accumulated rolling reduction is 45 percent. And cooling the rolled steel plate in air.
Table 2 heat treatment process of steel of each example
TABLE 3 mechanical properties in the tempered condition of the steels of the examples
The steel plate samples from the examples, and the simulated postweld heat treatment experiment is carried out, and the process is as follows: the heat preservation temperature is 620 plus or minus 10 ℃, the heat preservation time is 10 hours, the charging and discharging temperature is less than or equal to 425 ℃, and the heating and cooling rate is 56 ℃/h at the temperature of more than 425 ℃.
TABLE 4 mechanical Properties of the simulated postweld heat treatment of the steel molds of the examples
As shown in FIG. 1, the steel plate has a uniform tempered bainite structure in the thickness direction 1/4. The thickness specification of the steel plate designed by the invention reaches 101mm, the width specification of the steel plate reaches 4650mm, the welding seam length of the assembly can be effectively reduced from the perspective of safety of the nuclear containment, integration and integration of the containment are further realized, the utilization rate of the steel plate is high, and the safety is better. Compared with the common controlled rolling and heat treatment steel plate, the design of the same chemical components improves the comprehensive performance of the steel plate, the toughness of the obtained steel plate is good, especially the low-temperature impact toughness is greatly improved, and the production resource consumption of the steel plate is reduced.
In addition to the above embodiments, the present invention may have other embodiments. All technical solutions formed by adopting equivalent substitutions or equivalent transformations fall within the protection scope of the claims of the present invention.
Claims (5)
1. A SA738GrB steel plate for a nuclear power station containment is characterized in that: the thickness specification is 101mm, the width specification is 4650mm, and its chemical composition and mass percent are as follows: c is less than or equal to 0.2%, Si: 0.13-0.6%, Mn: 0.9 to 1.6 percent of Ni, less than or equal to 0.6 percent of Cr, less than or equal to 0.3 percent of Nb, less than or equal to 0.05 percent of Mo, less than or equal to 0.35 percent of V, less than or equal to 0.03 percent of Ti, and the balance of Fe and inevitable impurities.
2. The SA738GrB steel plate for the nuclear power station containment vessel as claimed in claim 1, wherein the chemical components and mass percentages are as follows: c: 0.15%, Mn: 1.53%, P: 0.009%, S: 0.001%, Si: 0.25%, Ni: 0.54%, Cr: 0.022%, Nb: 0.03%, Mo: 0.17%, V: 0.044%, Ti: 0.016%, Alt: 0.04%, and the balance of Fe and inevitable impurities.
3. The SA738GrB steel plate for the nuclear power station containment vessel as claimed in claim 1, wherein the chemical components and mass percentages are as follows: c: 0.14%, Mn: 1.55%, P: 0.008%, S: 0.001%, Si: 0.25%, Ni: 0.55%, Cr: 0.25%, Nb: 0.03%, Mo: 0.28%, V: 0.044%, Ti: 0.017%, Alt: 0.02%, and the balance of Fe and inevitable impurities.
4. The SA738GrB steel plate for the nuclear power station containment vessel as claimed in claim 1, wherein the chemical components and mass percentages are as follows: c: 0.13%, Mn: 1.55%, P: 0.009%, S: 0.001%, Si: 0.25%, Ni: 0.56%, Cr: 0.23%, Nb: 0.03%, Mo: 0.27%, V: 0.045%, Ti: 0.016%, Alt: 0.05%, and the balance of Fe and inevitable impurities.
5. The manufacturing method of the SA738GrB steel plate for the nuclear power station containment vessel applied to the claim 1 comprises the following steps of: the method comprises the following steps of molten steel pretreatment, converter smelting, refining, continuous casting, heating, rolling and heat treatment, and is characterized in that:
molten iron desulphurization pretreatment: the starting temperature is 1330-1370 ℃, the ending temperature is 1320-1350 ℃, 0.3-1.0 kg/ton magnesium powder and 2.5-4.0 kg/ton lime powder are sprayed, and S is less than or equal to 0.005 percent after the ending;
smelting and refining the molten steel, then carrying out continuous casting, wherein the superheat degree of the molten steel is 5-25 ℃, the throwing speed is 0.55-0.75 m/min, and carrying out continuous casting secondary cooling electromagnetic stirring: current 200-450A, frequency 5-7 Hz, light pressure: the reduction interval is 50-95%, the reduction is 4-8 mm, and the thickness of the continuous casting billet is 320 mm;
heating temperature of the continuous casting billet is 1180-1250 ℃, furnace time is 4.8-7.0 h, after the billet is discharged from a furnace and descaled, firstly, transverse rolling is carried out until the width of a finished product is wide, then longitudinal rolling is carried out, and rolling is carried out in two stages: the rolling temperature of the first stage is 1000-1150 ℃, and the accumulated reduction is 50-70%; in the second stage, the initial rolling thickness is 184mm, the accumulated reduction is 40-60%, and the rolled steel plate is cooled in air;
quenching: heating the steel plate in a quenching furnace, wherein the heating heat preservation temperature is 890-930 ℃, and the total heat preservation time is 2.1 min/mm; carrying out laminar cooling on the steel plate in a roller type quenching machine after heat preservation, wherein the laminar cooling process comprises a high-pressure section and a low-pressure section, the laminar pressure of the high-pressure section is 0.8MPa, the water-feeding-water ratio is 0.85, the laminar pressure of the low-pressure section is 0.5MPa, the water-feeding-water ratio is 0.88, and the roll gap of a roller of the quenching machine is set to be 101 mm; after the high-pressure section is cooled, the steel plate swings for more than 18min in the low-pressure section, and the integral temperature of the cooled steel plate is ensured to be below 100 ℃;
tempering: and (3) heating the steel plate in a tempering furnace to the tempering temperature of 660-680 ℃, preserving heat for more than 2.5min/mm, taking out of the furnace after heat preservation, and air cooling.
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GB2208201.0A GB2608271A (en) | 2019-11-15 | 2020-05-18 | SA738GRB steel plate for nuclear power plant containment and manufacturing method |
PCT/CN2020/090750 WO2021093293A1 (en) | 2019-11-15 | 2020-05-18 | Sa738grb steel plate for nuclear power plant containment and manufacturing method |
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WO2021093293A1 (en) * | 2019-11-15 | 2021-05-20 | 南京钢铁股份有限公司 | Sa738grb steel plate for nuclear power plant containment and manufacturing method |
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WO2021093293A1 (en) * | 2019-11-15 | 2021-05-20 | 南京钢铁股份有限公司 | Sa738grb steel plate for nuclear power plant containment and manufacturing method |
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CN115029628A (en) * | 2022-05-20 | 2022-09-09 | 首钢京唐钢铁联合有限责任公司 | High-quality super-thick steel plate and production method thereof |
CN115029628B (en) * | 2022-05-20 | 2023-10-24 | 首钢京唐钢铁联合有限责任公司 | High-quality super-thick steel plate and production method thereof |
CN116875904A (en) * | 2023-07-24 | 2023-10-13 | 鞍钢股份有限公司 | Steel plate for 750 MPa-grade petroleum storage tank and production method thereof |
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