CN112501496B - On-line quenching type double-phase low-yield-ratio steel plate and production method thereof - Google Patents
On-line quenching type double-phase low-yield-ratio steel plate and production method thereof Download PDFInfo
- Publication number
- CN112501496B CN112501496B CN202011121518.2A CN202011121518A CN112501496B CN 112501496 B CN112501496 B CN 112501496B CN 202011121518 A CN202011121518 A CN 202011121518A CN 112501496 B CN112501496 B CN 112501496B
- Authority
- CN
- China
- Prior art keywords
- steel plate
- rolling
- yield
- equal
- less
- 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
- 229910000831 Steel Inorganic materials 0.000 title claims abstract description 82
- 239000010959 steel Substances 0.000 title claims abstract description 82
- 238000010791 quenching Methods 0.000 title claims abstract description 26
- 230000000171 quenching effect Effects 0.000 title claims abstract description 26
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 18
- 238000005096 rolling process Methods 0.000 claims abstract description 84
- 238000001816 cooling Methods 0.000 claims abstract description 26
- 239000000126 substance Substances 0.000 claims abstract description 13
- 229910001563 bainite Inorganic materials 0.000 claims abstract description 10
- 239000012535 impurity Substances 0.000 claims abstract description 6
- 229910001568 polygonal ferrite Inorganic materials 0.000 claims abstract description 6
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 12
- 238000010438 heat treatment Methods 0.000 claims description 7
- 238000003723 Smelting Methods 0.000 claims description 5
- 238000009749 continuous casting Methods 0.000 claims description 5
- 238000007670 refining Methods 0.000 claims description 5
- 230000032683 aging Effects 0.000 claims description 3
- 238000006477 desulfuration reaction Methods 0.000 claims description 2
- 230000023556 desulfurization Effects 0.000 claims description 2
- 229910052742 iron Inorganic materials 0.000 claims description 2
- 238000001514 detection method Methods 0.000 claims 1
- 238000005070 sampling Methods 0.000 claims 1
- 238000010583 slow cooling Methods 0.000 claims 1
- 238000000034 method Methods 0.000 abstract description 24
- 238000005098 hot rolling Methods 0.000 abstract description 7
- 229910045601 alloy Inorganic materials 0.000 description 12
- 239000000956 alloy Substances 0.000 description 12
- 229910001566 austenite Inorganic materials 0.000 description 8
- 238000005728 strengthening Methods 0.000 description 8
- 230000009466 transformation Effects 0.000 description 8
- 229910052799 carbon Inorganic materials 0.000 description 6
- 239000000203 mixture Substances 0.000 description 6
- 230000009286 beneficial effect Effects 0.000 description 5
- 238000005266 casting Methods 0.000 description 5
- 229910000859 α-Fe Inorganic materials 0.000 description 5
- 239000006104 solid solution Substances 0.000 description 4
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 238000001953 recrystallisation Methods 0.000 description 3
- 238000005496 tempering Methods 0.000 description 3
- 238000005516 engineering process Methods 0.000 description 2
- 229910000734 martensite Inorganic materials 0.000 description 2
- 229910001562 pearlite Inorganic materials 0.000 description 2
- 238000001556 precipitation Methods 0.000 description 2
- 238000003466 welding Methods 0.000 description 2
- 238000005275 alloying Methods 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 230000018109 developmental process Effects 0.000 description 1
- 229910052840 fayalite Inorganic materials 0.000 description 1
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 description 1
- 239000010931 gold Substances 0.000 description 1
- 229910052737 gold Inorganic materials 0.000 description 1
- 238000005272 metallurgy Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 238000010899 nucleation Methods 0.000 description 1
- 230000006911 nucleation Effects 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- 239000002918 waste heat Substances 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Images
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
- 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
- C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
- C21D1/18—Hardening; Quenching with or without subsequent tempering
-
- 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
- C21D6/00—Heat treatment of ferrous alloys
- C21D6/005—Heat treatment of ferrous alloys containing Mn
-
- 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
- C21D6/00—Heat treatment of ferrous alloys
- C21D6/008—Heat treatment of ferrous alloys containing Si
-
- 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
-
- 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
- C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
- C21D9/0081—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for slabs; for billets
-
- 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
-
- 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
- C22C38/04—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
-
- 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
- C22C38/14—Ferrous alloys, e.g. steel alloys containing titanium or zirconium
-
- 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
- C21D2211/00—Microstructure comprising significant phases
- C21D2211/002—Bainite
-
- 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
- C21D2211/00—Microstructure comprising significant phases
- C21D2211/005—Ferrite
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Mechanical 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 an on-line quenching type double-phase low-yield-ratio steel plate and a production method thereof. The steel plate is designed by adopting low-cost components of low-C micro-Nb, and comprises the following chemical components in percentage by mass: c: 0.037-0.056%, Si: 0.15-0.20%, Mn: 1.28-1.58%, P is less than or equal to 0.015%, S is less than or equal to 0.008%, Nb: 0.022 to 0.042%, Ti: 0-0.015%, Al: 0.01-0.045%, and the balance of Fe and other inevitable impurities. The invention adopts a cooling process of two-stage rolling and on-line quenching after hot rolling to obtain a dual-phase structure of quasi-polygonal ferrite and bainite, the yield strength of a steel plate is 380-460 MPa, the tensile strength is 550-660 MPa, and the longitudinal impact energy is-40 ℃ KV2The steel plate is larger than or equal to 200J, the yield ratio is 0.60-0.75, the thickness is smaller than or equal to 24mm, and the strength and the yield ratio of 370-420 MPa bridge steel are well balanced.
Description
Technical Field
The invention belongs to the technical field of metallurgy, and relates to an on-line quenching type biphase low-yield-ratio steel plate and a production method thereof.
Background
With the rapid development of national economy, the demand on the strength of steel plates is higher and higher, the traditional production mode is to improve the strength of the steel plates by alloying, alloy elements are non-renewable resources, and the increase of the alloy elements will increase the alloy cost. The yield ratio is an important index for measuring the safety of bridge members, high-yield-ratio steel can be broken quickly after yielding, low-yield-ratio steel can be subjected to large strain strengthening after yielding, the steel can be broken only when reaching higher tensile strength, and the yield ratio of bridge steel is required to be less than or equal to 0.85 by bridge design units. In addition, as the strength of the steel sheet increases, the difficulty in controlling the yield ratio becomes greater. Therefore, new production processes need to be explored to achieve a good combination of low cost, high strength and low yield ratio.
The invention discloses a low-cost thick submarine pipeline steel plate and a manufacturing method thereof, the low-cost thick submarine pipeline steel plate adopts a low finish rolling temperature, firstly relaxes and slowly cools after rolling, then adopts an on-line quenching process to obtain a double-phase low-yield-ratio steel plate, firstly the low finish rolling temperature is large in equipment loss, secondly the relaxes and slowly cools to reduce the rolling efficiency, and the production control process is added for controlling the opening cooling temperature after relaxation. The invention discloses a low yield ratio hot rolled pipeline steel raw coil or uncoiled plate and a preparation method thereof, and is characterized in that 0.23% of Cr and 0.043% of Nb are high in component content, the final rolling temperature of the invention is 880-900 ℃, the temperature is high, deformation structures are easy to recover and grow, steel plate structures after cooling are thick and cannot meet the requirement of-40 ℃ impact performance, and the steel plate structures are quasi-polygonal ferrite and dispersed M/A or pearlite and degrade. The patent CN109628828A discloses a low yield ratio ultra-thick hydroelectric high-strength steel plate and a manufacturing method thereof, firstly the patent has higher component content, secondly, an online quenching and tempering process is adopted, the off-line tempering heat treatment cost is increased, in addition, the thickness of the steel plate is 80-150 mm, the yield ratio is easier to control when the steel plate is thicker, and the components and the process of the invention are not suitable for controlling the yield ratio of the thin steel plate. The patent CN101215624B discloses an on-line quenching production process method of a high-strength and high-toughness thick steel plate, which utilizes on-line quenching and high-temperature tempering to obtain the high-strength and high-toughness thick steel plate, and does not realize yield ratio control.
Disclosure of Invention
Aiming at various problems in the prior art, the invention aims to provide an on-line quenching type double-phase low-yield-ratio steel plate and a production method thereof. By reasonably designing chemical components and rolling and cooling processes, the low-cost component design of low-C micro-Nb is adopted; two-stage controlled rolling is adopted, the rough rolling finishing temperature and the high precision rolling finishing temperature are low; and a cooling process of on-line quenching after hot rolling to obtain a quasi-polygonal ferrite and bainite dual-phase structure, and finally obtaining the quasi-polygonal ferrite and bainite dual-phase structure with the thickness of less than or equal to 24mm, the yield strength of 380-460 MPa, the tensile strength of 550-660 MPa, the elongation A of more than or equal to 23 percent and the longitudinal impact energy of-40 ℃ KV2Not less than 200J; 5% strain aging impact energy-20 deg.C KV2The bridge steel is not less than 120J, and the yield ratio is 0.60-0.75.
In order to achieve the purpose, the invention adopts the following technical scheme:
an on-line quenching type double-phase low-yield-ratio steel plate and a production method thereof are disclosed, wherein the steel plate comprises the following chemical components in percentage by mass: c: 0.037-0.056%, Si: 0.15-0.20%, Mn: 1.28-1.58%, P is less than or equal to 0.015%, S is less than or equal to 0.008%, Nb: 0.022 to 0.042%, Ti: 0-0.015%, Al: 0.01-0.045%, and the balance of Fe and other inevitable impurities.
Preferably, Nb + Ti: 0.032-0.050%.
The following detailed analysis explains the effects of the components contained in the on-line quenched dual-phase low yield ratio steel plate and the selection of the use amounts of the components:
c: the C element forms a gap solid solution in Fe, has a good solid solution strengthening effect and is the cheapest strengthening element, but the toughness and the welding performance of steel are greatly damaged due to the increase of the C content, and in addition, the carbon content can be properly reduced by adopting an online quenching process, so that the C content is controlled to be 0.037-0.056%.
Si: the Si element forms a replacement solid solution in Fe, which is beneficial to controlling the yield ratio, but fayalite is easily formed due to excessively high Si content, the descaling is difficult, the surface quality of a steel plate is affected, and the Si is unfavorable for the low-temperature toughness of a welding joint, so that the Si content is controlled to be 0.15-0.20%.
Mn: mn element forms a replacement solid solution in Fe, is a commonly used strengthening element in steel, has relatively low alloy cost and is beneficial to reducing the yield ratio, but the increase of Mn element easily causes the increase of carbon equivalent, so the Mn content is controlled to be 1.28-1.58%.
Nb, Ti: nb and Ti are the most used microalloy elements, have good effects of fine grain strengthening and precipitation strengthening, and are beneficial to improving the strength and the toughness, but the yield ratio is easily increased due to the fine grain strengthening and the precipitation strengthening, the alloy cost of Nb and Ti is higher, and in addition, the online quenching process replaces the addition of part of alloy elements, so that the Nb and the Ti are controlled as follows: 0.032-0.050%
An on-line quenching type double-phase low-yield-ratio steel plate and a production method thereof comprise the following steps:
(1) firstly, carrying out molten iron pre-desulfurization treatment, smelting in a converter, refining in a steel ladle, and continuously casting into a casting blank with the thickness of 220 mm;
(2) then heating the continuous casting billet at the heating temperature of 1160-1200 ℃;
(3) the rolling process is controlled rolling in two stages, wherein the initial rolling temperature of rough rolling is 1020-1060 ℃, the initial rolling temperature of the last pass of rough rolling is 960-970 ℃, and the final rolling temperature of rough rolling is 960-970 ℃; the start rolling temperature of finish rolling is 890-940 ℃, and the finish rolling temperature is 870-840 ℃;
(4) and (3) carrying out on-line quenching and cooling on the steel plate after the hot rolling is finished, wherein the cooling rate is 35-60 ℃/s, and the final cooling temperature is less than or equal to 200 ℃/s.
Through proper design of chemical components and rolling and cooling processes, the good balance of strength, toughness and yield ratio of 370-420 MPa bridge steel is realized, the yield strength is 380-460 MPa, the tensile strength is 550-660 MPa, the elongation is more than or equal to 23 percent, and the longitudinal impact power is-40 ℃ KV2Not less than 200J, 5% strain aging impact energy-20 deg.C KV2Not less than 120J, and the yield ratio is 0.60-0.75.
(1) The low-carbon and low-alloy chemical composition design ensures that the steel plate firstly undergoes ferrite phase transformation in the rapid cooling process, and in the process of converting partial undercooled austenite into proeutectoid ferrite, carbon and alloy elements in the ferrite diffuse to surrounding untransformed austenite, so that the hardenability of the untransformed austenite is increased, and bainite phase transformation occurs when the steel plate is rapidly cooled to a bainite phase transformation region. The low-carbon and low-alloy chemical composition design enables the steel plate to generate enough ferrite structure even in the rapid cooling process, and ensures that the steel plate has relatively low yield strength.
(2) The initial rolling temperature of the last pass of rough rolling is controlled to be about 960 ℃, and the initial rolling temperature is critical temperature rolling, namely the initial rolling temperature is close to the recrystallization temperature (T)Then, the product is processed) The method can ensure that the last rolling is carried out in a recrystallization temperature range, can inhibit the growth of recrystallized grains, and effectively refines austenite grains.
(3) The finish rolling temperature is designed to be 870-840 ℃, and the austenite is rolled in a non-recrystallization region in the finish rolling stage, so that enough deformation tissue can be obtained, the steel plate is not easy to recover and grow, enough nucleation points are provided for phase change, the steel plate tissue is refined, and the steel plate has better low-temperature toughness; secondly, the relatively high finishing temperature can ensure enough heat energy reserve for on-line quenching.
(4) The on-line quenching process is characterized in that after hot rolling of a steel plate is finished, the steel plate is rapidly cooled and rapidly enters a bainite or martensite phase transformation interval to inhibit pearlite phase transformation, so that austenite which does not undergo ferrite phase transformation undergoes bainite or martensite phase transformation to obtain a harder lath structure, and the tensile strength of the steel plate is improved.
(5) The low-component design provides lower yield strength, the online quenching process provides higher tensile strength, and the low yield ratio control is realized through the coordinated design of the components and the process.
Compared with the prior art, the invention has at least the following beneficial effects:
(1) the low-carbon and low-alloy chemical component design reduces the alloy cost and improves the weldability of the steel plate; the low chemical composition design generates enough quasi-polygonal ferrite structure in the cooling process, and provides lower yield strength for the steel plate.
(2) The precise control of the rough rolling temperature effectively refines the austenite structure, the structure has heredity, the refinement of the original austenite structure enables the steel plate structure after phase transformation to be obviously refined, and the structure refinement improves the strength and the low-temperature toughness of the steel plate.
(3) The high finish rolling temperature reduces the rolling difficulty, reduces the rolling force requirement of the rolling mill and improves the rolling efficiency; in addition, the higher finish rolling temperature is easy to control the shape of the thin steel plate in the rolling process.
(4) The online quenching and cooling is a design idea of replacing gold with 'water', so that the waste heat of the hot rolled steel plate is effectively utilized, the addition of alloy elements is reduced, and the online quenching and cooling technology is a green production technology; in addition, the phase change of the steel plate is finished in the on-line quenching and cooling process, the steel plate does not have the problem of deformation caused by the phase change after being loaded on a cooling bed, and the plate shape control difficulty of the steel plate is reduced; and the design of on-line quenching is beneficial to obtaining a bainite structure, and bainite ensures higher tensile strength of the steel plate, so that the steel plate has lower yield ratio.
(5) The invention realizes good balance of the strength, the toughness and the yield ratio of the steel plate through the design of chemical components, a rolling process and a cooling mode, the yield strength is 380-460 MPa, the tensile strength is 550-660 MPa, and the longitudinal impact energy is-40 ℃ KV2Not less than 200J, and the yield ratio is 0.60-0.75.
Drawings
FIG. 1 is a photograph of a microstructure of example 1 taken 500 times at a longitudinal section 1/2 of a steel sheet;
FIG. 2 is a photograph of a microstructure of example 2 taken 500 times at a longitudinal section 1/2 of a steel sheet;
FIG. 3 is a photograph of a microstructure of example 3 taken 500 times at a longitudinal section 1/2 of a steel sheet;
Detailed Description
The technical solution of the present invention is further described in detail below with reference to the accompanying drawings and examples, but is not limited thereto.
Example 1
The steel plate comprises the following chemical components in percentage by mass: c: 0.055%, Si: 0.20%, Mn: 1.3%, P is less than or equal to 0.015%, S is less than or equal to 0.008%, Nb: 0.025%, Ti: 0.015%, Al: 0.03%, and the balance of Fe and other inevitable impurities.
Smelting in a converter, refining in a ladle, and continuously casting into a blank of 220 mm; the heating temperature of the continuous casting billet is 1180 ℃; the rolling process is two-stage rolling, wherein the initial rolling temperature of rough rolling is 1030 ℃, the initial rolling temperature of the last pass of rough rolling is 963 ℃, and the final rolling temperature of rough rolling is 960 ℃; the initial rolling temperature of finish rolling is 890 ℃, and the final rolling temperature is 860 ℃; after the hot rolling is finished, the steel plate is quenched on line, the cooling speed is 36 ℃/s, and the final cooling temperature is 150 ℃.
The mechanical properties of the steel sheets prepared by the composition and process are shown in table 1.
Example 2
The steel plate comprises the following chemical components in percentage by mass: c: 0.04%, Si: 0.18%, Mn: 1.5%, P is less than or equal to 0.015%, S is less than or equal to 0.008%, Nb: 0.035%, Ti: 0.010%, Al: 0.03%, and the balance of Fe and other inevitable impurities.
Smelting in a converter, refining in a ladle, and continuously casting into a blank of 220 mm; the heating temperature of the continuous casting billet is 1180 ℃; the rolling process is two-stage rolling, wherein the initial rolling temperature of rough rolling is 1020 ℃, the initial rolling temperature of the last pass of rough rolling is 968 ℃, and the final rolling temperature of rough rolling is 962 ℃; the initial rolling temperature of finish rolling is 910 ℃, and the final rolling temperature is 850 ℃; after the hot rolling is finished, the steel plate is quenched on line, the cooling speed is 44 ℃/s, and the final cooling temperature is 190 ℃.
The mechanical properties of the steel sheets prepared by the composition and process are shown in table 1.
Example 3
The steel plate comprises the following chemical components in percentage by mass: c: 0.045%, Si: 0.18%, Mn: 1.4%, P is less than or equal to 0.015%, S is less than or equal to 0.008%, Nb: 0.03%, Ti: 0.015%, Al: 0.03%, and the balance of Fe and other inevitable impurities.
Smelting in a converter, refining in a ladle, and continuously casting into a blank of 220 mm; the heating temperature of the continuous casting billet is 1180 ℃; the rolling process is two-stage rolling, wherein the initial rolling temperature of rough rolling is 1040 ℃, the initial rolling temperature of the last pass of rough rolling is 970 ℃, and the final rolling temperature of rough rolling is 960 ℃; the initial rolling temperature of finish rolling is 940 ℃, and the final rolling temperature is 870 ℃; after the hot rolling is finished, the steel plate is quenched on line, and the steel plate is cooled to room temperature at a cooling speed of 56 ℃/s.
The mechanical properties of the steel sheets prepared by the composition and process are shown in table 1.
Table 1 properties of examples
As can be seen from Table 1, the yield strength of the bridge steel plate with the thickness of 8-20 mm produced by the components and the process design is 398-433 MPa, the tensile strength is 584-644 MPa, the elongation is 25.0-26.6%, and the yield ratio is 0.62-0.74, and the impact energy KV at minus 40 ℃ is2Not less than 253J, and has excellent strength and toughness and lower yield ratio.
The above embodiments are merely illustrative of the technical idea of the present invention, and are intended to enable those skilled in the art to understand the contents of the present invention and implement the present invention, and the protection scope of the present invention is not limited thereby. All equivalent changes and modifications made according to the spirit of the present invention should be covered within the protection scope of the present invention.
Claims (3)
1. The production method of the on-line quenching type double-phase low-yield-ratio steel plate is characterized by comprising the following production process flows of: molten iron → desulfurization → converter smelting → ladle refining → continuous casting blank heating → dephosphorization → controlled rolling and controlled cooling → hot straightening → stacking and slow cooling → sampling detection → finished product, wherein the rolling process is controlled rolling in two stages, the initial rolling temperature of rough rolling is 1020-1060 ℃, and the final rolling temperature of rough rolling is 960-970 ℃; the start rolling temperature of finish rolling is 890-940 ℃, and the finish rolling temperature is 870-840 ℃; carrying out on-line quenching and cooling on the hot-rolled steel plate, wherein the cooling rate is 35-60 ℃/s, and the final cooling temperature is less than or equal to 200 ℃/s;
the steel plate comprises the following chemical components in percentage by mass: c: 0.037-0.056%, Si: 0.15-0.20%, Mn: 1.28-1.58%, P is less than or equal to 0.015%, S is less than or equal to 0.008%, Nb: 0.022-0.035%, Ti: 0 to 0.015 percentAl: 0.01-0.045%, and the balance of Fe and other inevitable impurities; the thickness of the steel plate is as follows: less than or equal to 24 mm; the steel plate structure is as follows: a quasi-polygonal ferrite and bainite dual-phase structure with well matched strength and yield ratio; the mechanical properties are as follows: the yield strength is 380-460 MPa, the tensile strength is 550-660 MPa, the elongation A is more than or equal to 23 percent, and the longitudinal impact energy is-40 ℃ KV2Not less than 200J, 5% strain aging impact energy-20 deg.C KV2Not less than 120J, and the yield ratio is 0.60-0.75.
2. The method for producing an in-line quenched dual-phase low yield ratio steel sheet according to claim 1, wherein the ratio of Nb + Ti: 0.032-0.050%.
3. The method for producing an on-line quenching type dual-phase low yield ratio steel plate as claimed in claim 1, wherein the initial rolling temperature of the last pass of rough rolling is 960-970 ℃.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN202011121518.2A CN112501496B (en) | 2020-10-20 | 2020-10-20 | On-line quenching type double-phase low-yield-ratio steel plate and production method thereof |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN202011121518.2A CN112501496B (en) | 2020-10-20 | 2020-10-20 | On-line quenching type double-phase low-yield-ratio steel plate and production method thereof |
Publications (2)
Publication Number | Publication Date |
---|---|
CN112501496A CN112501496A (en) | 2021-03-16 |
CN112501496B true CN112501496B (en) | 2022-01-04 |
Family
ID=74953956
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CN202011121518.2A Active CN112501496B (en) | 2020-10-20 | 2020-10-20 | On-line quenching type double-phase low-yield-ratio steel plate and production method thereof |
Country Status (1)
Country | Link |
---|---|
CN (1) | CN112501496B (en) |
Families Citing this family (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN114015934B (en) * | 2021-10-18 | 2023-02-28 | 武汉钢铁有限公司 | 600 MPa-level hot continuous rolling dual-phase structure axle housing steel and production method thereof |
CN114182081B (en) * | 2021-11-26 | 2023-12-01 | 湖南华菱湘潭钢铁有限公司 | Production method of ultra-thin ultra-wide low-temperature steel LT-FH32 |
CN114892102B (en) * | 2022-05-28 | 2023-08-15 | 日钢营口中板有限公司 | Economical steel plate for large-thickness pipe fitting and manufacturing method thereof |
CN116695023A (en) * | 2023-05-30 | 2023-09-05 | 鞍钢股份有限公司 | Steel for ultrahigh-strength and high-toughness low-yield-ratio longitudinal variable-thickness weather-resistant bridge and manufacturing method thereof |
Family Cites Families (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS6436724A (en) * | 1987-07-31 | 1989-02-07 | Sumitomo Metal Ind | Production of 60 kilogram class steel plate having low yield ratio |
CN102549189B (en) * | 2009-09-30 | 2013-11-27 | 杰富意钢铁株式会社 | Steel plate with low yield ratio, high strength, and high toughness and process for producing same |
JP5834534B2 (en) * | 2010-06-29 | 2015-12-24 | Jfeスチール株式会社 | High strength low yield ratio steel with high uniform elongation characteristics, manufacturing method thereof, and high strength low yield ratio welded steel pipe |
CN101985722B (en) * | 2010-09-20 | 2012-07-25 | 南京钢铁股份有限公司 | Pipeline steel plate with low yield ratio, fine grains and high strength and production method thereof |
CN102433507B (en) * | 2012-01-16 | 2013-12-25 | 江苏省沙钢钢铁研究院有限公司 | Low-yield-ratio easy-to-weld high-strength steel plate and preparation process thereof |
CN105463317B (en) * | 2015-11-25 | 2018-07-03 | 武汉钢铁有限公司 | Low yield strength ratio hot rolling pipe line steel reel or opening plate and preparation method thereof |
CN108220798B (en) * | 2018-03-22 | 2020-04-24 | 北京科技大学 | 460 MPa-level anti-seismic fireproof building steel and preparation method thereof |
CN110184525B (en) * | 2018-04-20 | 2021-06-22 | 江阴兴澄特种钢铁有限公司 | High-strength Q500GJE quenched and tempered steel plate for building structure and manufacturing method thereof |
CN109554523B (en) * | 2018-10-30 | 2020-11-13 | 江苏省沙钢钢铁研究院有限公司 | Heat treatment method for reducing yield ratio of low-carbon bainite bridge steel |
-
2020
- 2020-10-20 CN CN202011121518.2A patent/CN112501496B/en active Active
Also Published As
Publication number | Publication date |
---|---|
CN112501496A (en) | 2021-03-16 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
CN112501496B (en) | On-line quenching type double-phase low-yield-ratio steel plate and production method thereof | |
CN111979481B (en) | Thin-gauge low-yield-ratio high-strength bridge steel and production method thereof | |
CN103352167B (en) | A kind of low yield strength ratio high strength bridge steel plate and manufacture method thereof | |
CN107475620B (en) | Low-temperature pressure container quenching and tempering type A537Cl2 steel plate and its production method | |
CN111172465B (en) | Low-carbon equivalent large-thickness Q390GJ steel plate for building structure and manufacturing method thereof | |
CN101928885B (en) | Hydrothion corrosion resistant pipe steel and production method thereof | |
CN108546885B (en) | L555M pipeline steel with excellent low-temperature toughness and manufacturing method thereof | |
CN103320701B (en) | A kind of ferrite-bainite AHSS plate and manufacture method thereof | |
CN109504897A (en) | A kind of big thickness water power steel of 80kg grades of low-carbon-equivalent low-crackle sensitive and its manufacturing method | |
CN102691018A (en) | Low-compression ratio super-strength steel plate for ocean engineering and manufacturing method thereof | |
CN108517465B (en) | A kind of niobium titanium chromium-boron alloy abrasion-resistant stee and preparation method thereof | |
CN106834946B (en) | Big thickness protects Testing Tensile Strength at Elevated Temperature steel plate SA299GrB and preparation method thereof | |
CN105112782A (en) | Low-temperature ferrite LT-FH40 steel plate applied to hot-rolled ships and production method thereof | |
CN104372257A (en) | Low-alloy high-strength middle-thickness plate capable of utilizing self-tempering waste heat to improve toughness and preparation method of low-alloy high-strength middle-thickness plate | |
CN109628828A (en) | A kind of low yield strength ratio super thick water power high-strength steel sheet and its manufacturing method | |
CN102191430A (en) | Easy welding steel plate with yield strength of 550MPa and high toughness and manufacturing method thereof | |
CN102021489A (en) | Easily-welded aged high-strength steel and heat treatment process thereof | |
CN103540850B (en) | The super thick steel for engineering machinery of yield strength >=550MPa and production method | |
CN112063918B (en) | Pipeline steel plate for low-temperature high-toughness X90 steel grade hot-bending bend pipe and manufacturing method thereof | |
CN113846269A (en) | Cold-rolled high-weather-resistance steel plate with high strength and plasticity and preparation method thereof | |
CN111270169A (en) | Ni-containing alloy steel plate with excellent low-temperature toughness and production method thereof | |
CN108866435B (en) | Composite microalloyed medium manganese steel for automobile and manufacturing method thereof | |
CN111621713A (en) | Normalized rolled S460N thick steel plate and production method thereof | |
CN104862461A (en) | Preparation method for medium plate containing interphase-precipitated titanium carbide | |
CN116043128B (en) | 460E-grade super-thick steel plate and production 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 |