CN113046637A - High-temperature-resistant low-alloy steel plate and manufacturing method thereof - Google Patents

High-temperature-resistant low-alloy steel plate and manufacturing method thereof Download PDF

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CN113046637A
CN113046637A CN202110248472.9A CN202110248472A CN113046637A CN 113046637 A CN113046637 A CN 113046637A CN 202110248472 A CN202110248472 A CN 202110248472A CN 113046637 A CN113046637 A CN 113046637A
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temperature
steel plate
continuous casting
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胡战
马晓芹
李青麒
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Baosteel Zhanjiang Iron and Steel Co Ltd
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Baosteel Zhanjiang Iron and Steel Co Ltd
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    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C33/00—Making ferrous alloys
    • C22C33/04—Making ferrous alloys by melting
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21C—MANUFACTURE OF METAL SHEETS, WIRE, RODS, TUBES OR PROFILES, OTHERWISE THAN BY ROLLING; AUXILIARY OPERATIONS USED IN CONNECTION WITH METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL
    • B21C37/00—Manufacture of metal sheets, bars, wire, tubes or like semi-manufactured products, not otherwise provided for; Manufacture of tubes of special shape
    • B21C37/02—Manufacture of metal sheets, bars, wire, tubes or like semi-manufactured products, not otherwise provided for; Manufacture of tubes of special shape of sheets
    • 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
    • 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
    • C21D8/0247—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the heat treatment
    • C21D8/0263—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the heat treatment following 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
    • C22C38/002—Ferrous alloys, e.g. steel alloys containing In, Mg, or other elements not provided for in one single group C22C38/001 - C22C38/60
    • 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
    • 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
    • C22C38/12—Ferrous alloys, e.g. steel alloys containing tungsten, tantalum, molybdenum, vanadium, or niobium

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Heat Treatment Of Steel (AREA)

Abstract

The invention discloses a high-temperature-resistant low-alloy steel plate which comprises the following chemical components in percentage by mass: c: 0.17-0.20%, Si: 0.30-0.40%, Mn: 1.40-1.50%, P: less than or equal to 0.015%, S: less than or equal to 0.005 percent, Als: 0.015 to 0.030%, Nb: 0.012-0.020%, Ca: 0.001-0.004%, and the balance of Fe and inevitable trace impurity elements; smelting and casting raw material components of S1 to form a continuous casting billet, and controlling the temperature of tundish molten steel in the casting process to be 1520-1560 ℃; s2, heating the continuous casting slab, and keeping the temperature for 30min or more when the average temperature of the continuous casting slab reaches 1120-116 ℃ and 1180 ℃; s3, performing rough rolling and finish rolling on the heat-insulated continuous casting slab, and controlling the central part of the continuous casting slab to be more than 1000 ℃ and 800 ℃ at 750-; and S4, normalizing the semi-finished steel plate obtained in the step S3 to obtain the steel plate. The steel plate manufactured by the method is economic and strong in adaptability, does not contain elements such as Cr, Mo and V, can be used in a working environment at 400 ℃ for a long time, and still has excellent strength performance, the tensile strength is more than 490MPa, and the yield strength is more than 220 MPa.

Description

High-temperature-resistant low-alloy steel plate and manufacturing method thereof
Technical Field
The invention relates to the technical field of metallurgy, in particular to a low-alloy steel plate for high temperature resistance and a manufacturing method thereof.
Background
With the rapid development of national economy, the traditional power generation mode is not the optimal selection, and various countries begin to convert to new energy such as photo-thermal power generation, wind power generation and the like, for example, photo-thermal power generation is the preferred clean energy in middle east regions or wind power lack regions. However, the molten salt heat storage and cooling tank used for the photo-thermal power generation is in a relatively high-temperature working environment, such as high-temperature molten salt 386.4 ℃ and low-temperature molten salt 289.6 ℃, and the steel plate for equipment in the working environment is ensured to meet the strength performance requirement at 400 ℃. The traditional high-temperature steel plate has high alloy element content, is usually added with more Cr and V elements, is easy to crack in the production process, has complex production procedures and higher production difficulty, is easy to generate batch incompatibility in steel plate production, and the like, so the economic benefit is greatly influenced.
The invention application with the publication number of CN110512089A provides a preparation method of a high-temperature-resistant 3Cr-1Mo-0.25V alloy steel plate, which can meet the die welding temperature of 705 ℃ or higher, but the method adopts an electric furnace smelting method, needs a quenching and tempering process, and has large production difficulty and high cost of the 3Cr-1Mo-0.25V alloy steel plate. The invention application with the publication number of CN111074154A provides a large-thickness high-strength heat-resistant steel plate and a production method thereof, which can meet the requirements of stretching at the high temperature of 500 ℃, wherein the Rp0.2d strength is not lower than 290MPa, but the steel plate contains Mo and V alloys, has high Mn and Nb contents and high production cost, and the Mn and Nb contents do not meet the standards of carbon steel thick plates for American medium-temperature and low-temperature pressure vessels. Therefore, although the products proposed in the above patent documents have high temperature resistance, they have complicated production processes or high alloy contents, and the production cost is high. Therefore, the development of the high-temperature resistant low-alloy steel plate with low cost for replacing the existing alloy steel plate has important significance.
Disclosure of Invention
Aiming at the technical problems, the invention provides a low-alloy steel plate for high temperature resistance and a manufacturing method thereof, which do not contain elements such as Cr, Mo and V, have simple production process and low production cost.
Therefore, the invention provides a first technical scheme as follows:
a manufacturing method of a low-alloy steel plate for high temperature resistance comprises the following manufacturing steps of smelting, casting, heating, heat preservation, rolling, normalizing and the like:
s1, smelting and casting the raw material components to form a continuous casting billet, controlling the temperature of tundish molten steel in the casting process to be 1520-1560 ℃,
the raw materials comprise the following components in percentage by mass: c: 0.17-0.20%, Si: 0.30-0.40%, Mn: 1.40-1.50%, P: less than or equal to 0.015%, S: less than or equal to 0.005 percent, Als: 0.015 to 0.030%, Nb: 0.012-0.020%, Ca: 0.001-0.004%, and the balance of Fe and inevitable trace impurity elements;
s2, heating the continuous casting slab, and keeping the temperature for at least 30min when the average temperature of the continuous casting slab reaches 1120-116 ℃ and 1180 ℃;
s3, performing rough rolling and finish rolling on the heat-insulated continuous casting slab, wherein the temperature of the central part of the continuous casting slab is over 1000 ℃ in the rough rolling stage, and the temperature of the central part of the continuous casting slab is 750-plus 800 ℃ in the finish rolling stage, so as to obtain a semi-finished product steel plate;
s4, normalizing the semi-finished steel plate at 860-910 deg.C, and air cooling.
The design basis of the components and the contents is as follows:
c has great influence on the strength and the low-temperature toughness of the steel, and the content of C in the steel is expected to be controlled to be lower from the improvement of the low-temperature toughness of the steel; however, the C content is not too low from the viewpoint of the strength of the steel, the strength under high-temperature service and the control of the microstructure in the production and manufacturing process, so that the C content is 0.17-0.20 percent.
Si promotes deoxidation of molten steel and can improve the strength of a steel plate; although Si can improve the strength of the steel sheet, Si increases the degree of solidification segregation of molten steel, seriously deteriorates the low-temperature toughness of the steel sheet, and the Si content is controlled to 0.30 to 0.40% in consideration of the economical efficiency and workability of the steel making process.
Mn is used as the most important alloy element in the steel, not only the strength of the steel plate is improved, but also the effects of expanding an austenite phase region, reducing the Ar3 point temperature and refining ferrite grains so as to improve the low-temperature toughness of the steel plate are achieved, and the content of the internally controlled Mn in the steel cannot be lower than 1.35 percent. Mn is easy to segregate in the molten steel solidification process, particularly, the excessively high Mn content (when the Mn content is more than 1.60%) is easy to generate conjugate segregation with elements such as C, P, S and the like, so that the segregation and the porosity of the center of a continuous casting slab are aggravated, the serious center segregation of the continuous casting slab is easy to form an abnormal structure in the subsequent controlled rolling and welding processes, and coarse MnS particles can be formed due to the excessively high Mn content, extend along the rolling direction in the hot rolling process, seriously deteriorate the impact toughness of a base metal steel plate (particularly in the transverse direction) and a welding Heat Affected Zone (HAZ), and have poor lamellar tearing resistance; in addition, the upper limit of the Mn content is 1.50% in the standards for thick carbon steel plates for medium-and low-temperature pressure vessels in the United states. In view of the compositional compatibility, the Mn content in the steel is 1.40-1.50%.
P has great damage effect on the mechanical properties of steel, particularly low-temperature impact toughness and weldability as harmful impurities in the steel, and theoretically, the lower the content of P is, the better the steel is, but the content of P needs to be controlled to be less than or equal to 0.015 percent in consideration of steelmaking operability and steelmaking cost.
S has a great damage effect on the low-temperature toughness of steel as harmful inclusions in the steel, more importantly, S is combined with Mn in the steel to form MnS inclusions, the plasticity of MnS enables the MnS to extend along the rolling direction in the hot rolling process to form MnS inclusion bands along the rolling direction, the impact toughness (especially transverse impact toughness), Z-direction performance and weldability of a steel plate are seriously damaged, and S is also a main element generating hot brittleness in the hot rolling process. Theoretically, the lower the requirement, the better, but considering the steelmaking operability, the steelmaking cost and the logistics smoothness principle, the S content needs to be controlled to be less than or equal to 0.005 percent for the requirement of toughness at the temperature of-20 ℃.
Als in the steel plate can fix free [ N ] in the steel, more importantly, HAZ free [ N ] in a welding heat affected zone is reduced, and the low-temperature impact toughness of the welding HAZ is improved; however, excessive addition of Als in the steel can form a large amount of dispersed needle-shaped Al2O3 inclusions in the steel, and the low-temperature impact toughness and weldability of the steel plate are seriously damaged, so that the optimal Als content is controlled to be between 0.015 and 0.030 percent.
Als in the steel plate can fix free [ N ] in the steel, more importantly, HAZ free [ N ] in a welding heat affected zone is reduced, and the low-temperature impact toughness of the welding HAZ is improved; however, excessive addition of Als in the steel can form a large amount of dispersed needle-shaped Al2O3 inclusions in the steel, and the low-temperature impact toughness and weldability of the steel plate are seriously damaged, so that the optimal Als content is controlled to be between 0.015 and 0.030 percent.
The Ca treatment of the steel can further purify the molten steel on one hand, and the modification treatment of the sulfide in the steel on the other hand can lead the sulfide to become non-deformable, stable and fine spherical sulfide, inhibit the hot brittleness of S, improve the low-temperature toughness and Z-direction performance of the steel and improve the anisotropy of the toughness of the steel plate. The addition amount of Ca depends on the content of S in steel, the addition amount of Ca is too low, and the treatment effect is not great; the addition of Ca is too high, the formed Ca (O, S) has too large size, the number of inclusions in the steel is increased, the brittleness is also increased, the steel can become a fracture crack starting point, the low-temperature toughness and the weldability of the steel are reduced, the purity of the steel is also reduced, and the steel liquid is polluted, so the proper range of the Ca content is 0.001-0.004%.
Preferably, the accumulated reduction rate of rough rolling is more than or equal to 60%, and the reduction rate of rolling passes is more than or equal to 12% and is not less than 1 pass.
Preferably, the cumulative reduction rate of finish rolling is more than or equal to 40%, the reduction rate of rolling pass is more than or equal to 9% and is not less than 1 pass, and the reduction rate of last pass is more than or equal to 7%.
The invention proposes a second technical solution as follows:
a low-alloy steel plate for high temperature resistance is prepared by the preparation method.
Preferably, the thickness of the steel plate is 10-60 mm.
Compared with the prior art, the invention has the beneficial effects that:
the high-temperature-resistant low-alloy steel plate and the manufacturing method thereof provided by the invention get rid of the characteristics of uneconomical performance and great difficulty of the production difficulty of the traditional high-temperature-resistant steel plate by adding more elements such as Cr, Mo and V, and the like, and meanwhile, the design meets the standard of carbon steel thick plates for American medium and low temperature pressure vessels, and the adaptability is strong; the steel plate can be used in a working environment at 400 ℃ for a long time and has excellent mechanical strength performance.
Drawings
FIG. 1 is a microstructure diagram of example 3 of the present invention.
Detailed Description
The following further describes a specific embodiment of the present invention with reference to the drawings by using specific examples, which are intended to describe the technical solution in detail, but not to limit the technical solution. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Example 1
The chemical components of the high-temperature resistant low-alloy steel plate provided by the invention are as follows:
C:0.1885％，Si:0.3547％，Mn:1.435％，P：0.0130％，S：0.0049％，Als：0.0234％，Nb:0.0144％，Ca：0.0021％。
the method for manufacturing the high-temperature resistant low-alloy steel plate comprises the following steps:
s1, smelting and casting according to chemical components of the steel plate in the embodiment 1 in the table 1 to form a continuous casting billet, wherein the thickness of the continuous casting billet is 227mm, and the temperature of tundish molten steel in casting is controlled to be 1540 ℃;
s2, heating the continuous casting slab, and keeping the temperature for 31min when the average temperature of the continuous casting slab reaches 1156 ℃;
s3, the first stage rolling is a rough rolling stage, so that dynamic/static recrystallization of the rolled material is ensured, and austenite grains are refined; therefore, the accumulated reduction rate is 68.3 percent, the temperature of a rolling center part in a rough rolling stage is 1075 ℃, and the reduction rate of each pass of 1 pass of rolling is more than or equal to 12 percent; the second stage is a finish rolling stage, the proper initial rolling temperature and pass are controlled to ensure that the core temperature of the final-rolled steel plate is 771 ℃, the accumulated reduction rate is 72.2 percent, the reduction rate of the pass containing 6 passes is more than or equal to 9 percent, and the reduction rate of the last pass is 8.1 percent, so that a semi-finished steel plate is obtained;
and S4, normalizing the semi-finished steel plate at the heat treatment temperature of 901 ℃, treating in a furnace for 50min, discharging the steel plate out of the furnace, and air-cooling to obtain the steel plate with the finished product thickness of 20 mm.
Example 2
The chemical components of the high-temperature resistant low-alloy steel plate provided by the invention are as follows:
C:0.1919％，Si:0.3534％，Mn:1.445％，P：0.0119％，S：0.0047％，Als：0.0275％，Nb:0.0169％，Ca：0.0018％。
the method for manufacturing the high-temperature resistant low-alloy steel plate comprises the following steps:
s1, smelting and casting according to chemical components of the steel plate in the embodiment 2 in the table 1 to form a continuous casting billet, wherein the thickness of the continuous casting billet is 227mm, and the temperature of tundish molten steel is controlled to be 1544 ℃ during casting;
s2, heating the continuous casting slab, and keeping the temperature for 42min when the average temperature of the continuous casting slab reaches 1149 ℃;
s3, the first stage rolling is a rough rolling stage, so that dynamic/static recrystallization of the rolled material is ensured, and austenite grains are refined; therefore, the accumulated reduction rate is 62.6 percent, the temperature of the initial rolling core part in the rough rolling stage is 1025 ℃, and the reduction rate of each pass of 2 passes of rolling is more than or equal to 12 percent; the second stage is a finish rolling stage, the proper initial rolling temperature and pass guarantee final rolled steel plate core temperature are controlled to 762 ℃, the cumulative reduction rate is 64.7 percent, the pass rolling reduction rate is more than or equal to 9 percent, and the final pass secondary reduction rate is 7.4 percent, so as to obtain a semi-finished steel plate;
and S4, normalizing the semi-finished steel plate at 882 ℃, treating in a furnace for 65min, discharging the steel plate out of the furnace, and air-cooling to obtain the finished product with the thickness of 30 mm.
Example 3
The chemical components of the high-temperature resistant low-alloy steel plate provided by the invention are as follows:
C:0.1949％，Si:0.3435％，Mn:1.474％，P：0.0135％，S：0.0029％，Als：0.0287％，Nb:0.017％，Ca：0.0023％。
the method for manufacturing the high-temperature resistant low-alloy steel plate comprises the following steps:
s1, smelting and casting according to chemical components of the steel plate in the embodiment 3 in the table 1 to form a continuous casting billet, wherein the thickness of the continuous casting billet is 227mm, and the temperature of tundish molten steel is controlled at 1538 ℃ during casting;
s2, heating the continuous casting slab, and keeping the temperature for 36min when the average temperature of the continuous casting slab reaches 1121 ℃;
s3, the first stage rolling is a rough rolling stage, so that dynamic/static recrystallization of the rolled material is ensured, and austenite grains are refined; therefore, the accumulated reduction rate is 68.3 percent, the temperature of a rolling center part in a rough rolling stage is 1037 ℃, and the reduction rate of each pass of 2 passes of rolling is more than or equal to 12 percent; the second stage is a finish rolling stage, the proper initial rolling temperature and pass are controlled to ensure that the core temperature of the final-rolled steel plate is 751 ℃, the cumulative reduction rate is 44.4 percent, the reduction rate of pass of 2 passes is more than or equal to 9 percent, and the reduction rate of the last pass is 8.6 percent, so that a semi-finished steel plate is obtained;
s4, normalizing the semi-finished steel plate at the heat treatment temperature of 890 ℃, treating in a furnace for 89min, discharging the steel plate out of the furnace, and air-cooling to obtain the steel plate with the finished product thickness of 40 mm.
Example 4
The chemical components of the high-temperature resistant low-alloy steel plate provided by the invention are as follows:
C:0.187％，Si:0.3582％，Mn:1.469％，P：0.0123％，S：0.0032％，Als：0.0244％，Nb:0.017％，Ca：0.0017％。
the method for manufacturing the high-temperature resistant low-alloy steel plate comprises the following steps:
s1, smelting and casting according to chemical components of the steel plate in the embodiment 4 in the table 1 to form a continuous casting billet, wherein the thickness of the continuous casting billet is 227mm, and the temperature of tundish molten steel is controlled at 1550 ℃ during casting;
s2, heating the continuous casting slab, and keeping the temperature for 41min when the average temperature of the continuous casting slab reaches 1135 ℃;
s3, the first stage rolling is a rough rolling stage, so that dynamic/static recrystallization of the rolled material is ensured, and austenite grains are refined; therefore, the accumulated reduction rate is 60.4 percent, the temperature of the rolling center part in the rough rolling stage is 1040 ℃, and the reduction rate of each pass of 1 pass of rolling is more than or equal to 12 percent; the second stage is a finish rolling stage, the proper initial rolling temperature and pass are controlled to ensure that the core temperature of the final-rolled steel plate is 767 ℃, the cumulative reduction rate is 44.4 percent, the reduction rate of the pass of 1 pass is more than or equal to 9 percent, and the reduction rate of the last pass is 7.7 percent, so that a semi-finished steel plate is obtained;
s4, normalizing the semi-finished steel plate at the heat treatment temperature of 870 ℃ in a furnace for 110min, and discharging the steel plate out of the furnace for air cooling to obtain the steel plate with the finished product thickness of 50 mm.
Comparative example 1
The chemical composition of the low alloy steel sheet for high temperature resistance provided in comparative example 1 is as follows:
C:1907％，Si:0.3102％，Mn:1.288％，P：0.0118％，S：0.0028％，Als：0.0264％，Nb:0.016％，Ca：0.0026％。
the provided material has low Mn, and the manufacturing method of the steel plate comprises the following steps:
s1, smelting and casting according to the chemical components of the steel plate of the comparative example 1 in the table 1 to form a continuous casting billet, wherein the thickness of the continuous casting billet is 227mm, the temperature of tundish molten steel during casting is controlled to be 1542 ℃, and the mass percent of Mn is 1.288%;
s2, heating the continuous casting slab, and keeping the temperature for 37min when the average temperature of the continuous casting slab reaches 1138 ℃;
s3, the first stage rolling is a rough rolling stage, so that dynamic/static recrystallization of the rolled material is ensured, and austenite grains are refined; therefore, the accumulated reduction rate is 68.3 percent, the temperature of the rolling center part in the rough rolling stage is 1030 ℃, and the reduction rate of each rolling pass containing 2 passes is more than or equal to 12 percent; the second stage is a finish rolling stage, the proper initial rolling temperature and pass are controlled to ensure that the core temperature of the final-rolled steel plate is 755 ℃, the cumulative reduction rate is 44.4 percent, the reduction rate of the pass of 2 passes is 9 percent, and the reduction rate of the last pass is 8.3 percent, so that a semi-finished steel plate is obtained;
and S4, normalizing the semi-finished steel plate at the heat treatment temperature of 886 ℃, treating in a furnace for 85min, discharging the steel plate out of the furnace, and air-cooling to obtain the steel plate with the finished product thickness of 40 mm.
Comparative example 2
The chemical components of the high-temperature resistant low-alloy steel plate provided by the invention are as follows:
C:1947％，Si:0.3536％，Mn:1.440％，P：0.0140％，S：0.0032％，Als：0.0282％，Nb:0.0183％，Ca：0.0022％。
the provided method for manufacturing the steel plate is not subjected to normalizing treatment, and comprises the following steps:
s1, smelting and casting according to the chemical components of the steel plate of the comparative example 2 in the table 1 to form a continuous casting billet, wherein the thickness of the continuous casting billet is 227mm, and the temperature of tundish molten steel is controlled to be 1546 ℃ during casting;
s2, heating the continuous casting slab, and keeping the temperature for 40min when the average temperature of the continuous casting slab reaches 1140 ℃;
s3, the first stage rolling is a rough rolling stage, so that dynamic/static recrystallization of the rolled material is ensured, and austenite grains are refined; therefore, the accumulated reduction rate is 68.3 percent, the temperature of the initial rolling core part in the rough rolling stage is 1035 ℃, and the reduction rate of each rolling pass containing 2 passes is more than or equal to 12 percent; the second stage is a finish rolling stage, the proper initial rolling temperature and pass are controlled to ensure that the core temperature of the final-rolled steel plate is 755 ℃, the accumulated reduction rate is 44.4 percent, the reduction rate of pass of 2 passes is more than or equal to 9 percent, and the reduction rate of the last pass is 8.3 percent, so that a finished steel plate is obtained, and the thickness of the finished product is 40 mm.
To better illustrate the effects of the present invention, the steel sheets prepared in examples 1 to 4 and comparative examples 1 to 2 were subjected to performance tests.
First, a typical microstructure photograph of the steel sheet manufactured in example 3 was shown in fig. 1.
And (3) testing results: from the microstructure photograph of fig. 1, it was confirmed that the metallographic structure thereof was ferrite + pearlite.
And (II) mechanical property detection is carried out on examples 1-4 and comparative examples 1-2.
The test method comprises the following steps: (1) tensile strength Rm, elongation strength rp0.2, and elongation a: testing according to GB/T228.1-2010 metal material tensile test; (2) impact Akv at-20 ℃: the test is carried out according to GB/T229-2007 method for testing the Charpy impact of the metallic materials.
And (3) testing results: the test results of examples 1 to 4 and comparative examples 1 to 2 are shown in Table 1.
TABLE 1 test of Steel sheet Properties
Figure BDA0002963241140000061
Figure BDA0002963241140000071
As can be seen from Table 1, the low alloy steel plate provided by the embodiment of the invention not only has excellent tensile strength at normal temperature and conventional impact energy at-20 ℃ of more than 180J, but also has very good tensile strength Rm and yield strength Rp0.2 at high temperature of 400 ℃, wherein the tensile strength Rm is more than 490MPa, and the yield strength Rp0.2 is more than 220 MPa. Particularly, the performance of the embodiment 1 is optimal, the tensile strength Rm reaches 544MPa, and the yield strength Rp0.2 reaches 253MPa, which are obviously better than those of the comparative examples 1 and 2.
Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims (5)

1. A manufacturing method of a low-alloy steel plate for high temperature resistance comprises the processes of smelting, casting, heating, heat preservation, rolling, normalizing and the like, and is characterized by comprising the following manufacturing steps:
s1, smelting and casting the raw material components to form a continuous casting billet, controlling the temperature of tundish molten steel in the casting process to be 1520-1560 ℃,
the raw materials comprise the following components in percentage by mass: c: 0.17-0.20%, Si: 0.30-0.40%, Mn: 1.40-1.50%, P: less than or equal to 0.015%, S: less than or equal to 0.005 percent, Als: 0.015 to 0.030%, Nb: 0.012-0.020%, Ca: 0.001-0.004%, and the balance of Fe and inevitable trace impurity elements;
s2, heating the continuous casting slab, and keeping the temperature for at least 30min when the average temperature of the continuous casting slab reaches 1120-116 ℃ and 1180 ℃;
s3, performing rough rolling and finish rolling on the heat-insulated continuous casting slab, wherein the temperature of the central part of the continuous casting slab is over 1000 ℃ in the rough rolling stage, and the temperature of the central part of the continuous casting slab is 750-plus 800 ℃ in the finish rolling stage, so as to obtain a semi-finished product steel plate;
s4, normalizing the semi-finished steel plate at 860-910 deg.C, and air cooling.
2. The method for manufacturing a low-alloy steel sheet for high temperature resistance according to claim 1, wherein the integrated reduction rate of rough rolling is not less than 60%, and the reduction rate of rolling passes is not less than 12% and not less than 1 pass.
3. The method for producing a high-temperature-resistant low-alloy steel sheet as claimed in claim 1, wherein the cumulative reduction of the finish rolling is not less than 40%, the reduction of the rolling pass is not less than 9% and not less than 1, and the reduction of the final pass is not less than 7%.
4. A low-alloy steel sheet for high temperature resistance, which is obtained by the production method according to any one of claims 1 to 5.
5. The low alloy steel sheet for high temperature resistance according to claim 6, wherein the steel sheet has a thickness of 10 to 60 mm.
CN202110248472.9A 2021-03-05 2021-03-05 High-temperature-resistant low-alloy steel plate and manufacturing method thereof Pending CN113046637A (en)

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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH09202919A (en) * 1996-01-24 1997-08-05 Nippon Steel Corp Production of high tensile strength steel material excellent in toughness at low temperature
CN101838768A (en) * 2010-04-09 2010-09-22 武汉钢铁(集团)公司 Low-temperature impact resistant steel for hot-rolling U-type steel sheet pile and production method thereof
JP2016089188A (en) * 2014-10-30 2016-05-23 Ｊｆｅスチール株式会社 Thick steel plate and method of producing the same
CN109022667A (en) * 2018-09-21 2018-12-18 南阳汉冶特钢有限公司 A kind of Q420D super-thick steel plate and its production method
CN110317999A (en) * 2019-07-24 2019-10-11 宝钢湛江钢铁有限公司 It is a kind of to roll state steel plate and its manufacturing method with low-temperature impact toughness

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH09202919A (en) * 1996-01-24 1997-08-05 Nippon Steel Corp Production of high tensile strength steel material excellent in toughness at low temperature
CN101838768A (en) * 2010-04-09 2010-09-22 武汉钢铁(集团)公司 Low-temperature impact resistant steel for hot-rolling U-type steel sheet pile and production method thereof
JP2016089188A (en) * 2014-10-30 2016-05-23 Ｊｆｅスチール株式会社 Thick steel plate and method of producing the same
CN109022667A (en) * 2018-09-21 2018-12-18 南阳汉冶特钢有限公司 A kind of Q420D super-thick steel plate and its production method
CN110317999A (en) * 2019-07-24 2019-10-11 宝钢湛江钢铁有限公司 It is a kind of to roll state steel plate and its manufacturing method with low-temperature impact toughness

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
韩喆 等: "《金属材料与热处理》", 31 December 2013 *

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