CN110846564A - Low-cost high-strength beam steel 750L and production method thereof - Google Patents

Low-cost high-strength beam steel 750L and production method thereof Download PDF

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Publication number
CN110846564A
CN110846564A CN201910943515.8A CN201910943515A CN110846564A CN 110846564 A CN110846564 A CN 110846564A CN 201910943515 A CN201910943515 A CN 201910943515A CN 110846564 A CN110846564 A CN 110846564A
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China
Prior art keywords
steel
temperature
equal
strength beam
controlled
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CN201910943515.8A
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Chinese (zh)
Inventor
许斌
李红俊
吕德文
贾改风
李斌
张继永
王文录
李冠楠
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Handan Iron and Steel Group Co Ltd
HBIS Co Ltd Handan Branch
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Handan Iron and Steel Group Co Ltd
HBIS Co Ltd Handan Branch
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Priority to CN201910943515.8A priority Critical patent/CN110846564A/en
Publication of CN110846564A publication Critical patent/CN110846564A/en
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    • 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
    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C21D8/0205—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips of ferrous alloys
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C21D8/0221—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the working steps
    • C21D8/0226—Hot rolling
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • 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
    • C21D2211/004—Dispersions; Precipitations
    • 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

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  • 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 relates to low-cost high-strength beam steel 750L, which comprises the following chemical components in percentage by mass: c: 0.065-0.085%, Si: 0.05-0.15%, Mn: 1.30-1.70%, P is less than or equal to 0.015%, S is less than or equal to 0.004%, Nb: 0.035 to 0.050%, Ti: 0.080-0.100%, Als: 0.015-0.035%, V: 0.040-0.050%, 0-0.0020% of B, less than or equal to 0.005% of N, and the balance of Fe and impurities within an allowable range. The production method comprises the working procedures of molten iron pretreatment, smelting, continuous casting, casting blank heating, controlled rolling and laminar cooling. The high-strength beam steel 750L produced by the method has low cost and good low-temperature impact toughness.

Description

Low-cost high-strength beam steel 750L and production method thereof
Technical Field
The invention belongs to the technical field of metallurgical rolling, and particularly relates to low-cost high-strength beam steel 750L and a production method thereof.
Background
750L belongs to high strength automobile girder steel, mainly used commercial car girder processing. At present, under the pressure of energy conservation and environmental protection, the elimination of old commercial vehicles is greatly accelerated by China, and the over-limit overload treatment force is increased. The light-weight steel for the commercial vehicle is selected, so that the weight of the vehicle can be reduced, the effective load is improved, and the total fuel consumption can be effectively reduced. With the increasing market proportion of new energy commercial vehicles, the light weight is also the key for solving the problem of the endurance mileage of the new energy vehicles. The main forming mode of the automobile beam steel plate is as follows: the steel plate of the girder has high requirements on flattening longitudinal shearing, bending forming and welding assembly, and needs to have high toughness, fatigue resistance and cold formability.
The light weight of the commercial vehicle is concerned by the whole industry chain at present, and the great progress is made, and in the aspect of material use, domestic material selection still has a gap with the world advanced level. Advanced high-strength steel, aluminum alloy, magnesium alloy, non-metal composite materials and the like are used on domestic commercial vehicles, so that the light weight, safety and reliability of the commercial vehicles are promoted, but the application proportion and the application maturity of the advanced materials of the commercial vehicles in China are lower than those of the domestic advanced level. In the aspect of chassis and girder steel, at present, 510-610L 650MPa girder steel plates are mainly used in China, and 700-800 MPa girder steel plates are used in a small number of vehicle types. The strength of the common steel for the frames of international advanced commercial vehicles reaches the level of 700 MPa-800 MPa. Some companies have also adopted heat treated vehicle frames above the 1200MPa level, even aluminum alloy vehicle frames. The weight of the frame is obviously lower than that of the domestic similar products, and the domestic development of the ultrahigh-strength girder steel is imperative.
The existing 750L steel factory for mass supply mainly adopts a low C + high Mn and Nb and Ti composite strengthening system, and a small amount of noble metal Mo is added. The component system has high Ti content, generally between 0.110 and 0.130wt%, high Mn content, generally between 1.85 and 2.05wt%, and about 350 yuan increase of cost by adding 0.15 to 0.30wt% of Mo alloy. During production, TiN inclusions are more, the banded structure of a finished product