Thin hot forming steel directly rolled through thin slab and having tensile strength larger than or equal to 2100 MPa and production method

Abstract

Thin hot forming steel directly rolled through a thin slab and having tensile strength larger than or equal to 2100 MPa comprises components including, by weight percent, 0.41% to 0.50% of C, 0.45% to 0.65% of Si, 1.6% to 2.0% of Mn, not larger than 0.006% of P, not larger than 0.004% of S, 0.015% to 0.060% of Als, 0.50% to 0.65% of Cr, 0.004% to 0.005% of B, 0.046% to 0.060% of Ti or 0.046% to 0.060% of Nb or 0.046% to 0.060% of V or compounding of two or more of Ti, Nb and V, 0.36% to 0.60% of Mo, 0.21% to 0.35% of Ni and not larger than 0.004% of N. Production steps comprise molten iron desulfuration, electric furnace or converter smelting and refining, continuous casting, descaling treatment before the steel enters a soaking pit furnace, uniform heating, heating, high-pressure water descaling before the steel enters a rolling mill, rolling, cooling, reeling, austenitizing, mold punching molding and quenching. The strength is high, the manufacturing flow is short, the product surface quality is good, the thickness precision can be controlled within +/-0.03 mm, energy consumption can be greatly saved, and in addition, the steel and the method have the important significance in automobile light weight.

Description

technical field [0001] The invention relates to a steel for auto parts and a production method thereof, in particular to a thin hot-formed steel with a tensile strength ≥ 2100 MPa directly rolled by a thin slab and a production method thereof, and is suitable for production of products with a thickness of 0.8 to 2mm . Background technique [0002] With the development of the automobile industry and the gradual development of automobile design and manufacturing in the direction of energy saving, environmental protection and safety, automobile lightweight has become the mainstream direction of automobile design at present and for a long time to come. [0003] The study found that the vehicle's vehicle weight and energy consumption have a linear relationship. According to statistics, every 10% reduction in vehicle weight can increase fuel efficiency by 6% to 8%. One of the most important ways to reduce the weight of automobiles is to use high-strength and ultra-high-strength ...

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Problems solved by technology

[0006] The present invention overcomes the low strength level existing in the prior art and cannot meet the needs of users for high-strength parts, and provides a method that can not only meet the requirements of automobile design for ultra-high-strength mechanical properties, but also successfully complete complex deformation, and the deformation Thin hot-formed steel with tensile strength ≥ 2100MPa directly rolled with thin slabs and high dimensional accuracy of parts and its production method

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