Hot forming steel produced through ESP production line and having tensile strength larger than or equal to 1800 MPa and method

Abstract

The invention discloses hot forming steel produced through an ESP production line and having tensile strength larger than or equal to 1800 MPa. The steel comprises, by weight percent, 0.28 to 0.40% ofC, 0.15 to 0.40% of Si, 1.40 to 1.60% of Mn, not larger than 0.01% of P, not larger than 0.01% of S, 0.015 to 0.050% of Als, not larger than 0.80% of Cr, not larger than 0.005% of N, 0.002 to 0.005%of B, not larger than 0.50% of Mo, and 0.025 to 0.090% of Nb+Ti. The production method comprises the steps of smelting and continuous casting to form a plate blank; rough rolling; soaking; finish rolling after conventional high-pressure descaling; laminar cooling; heating; punching molding after acid pickling. Nb and Ti are added in a composite manner, elements of Cr, B, Mo and the like in the components are controlled, the ESP short-flow technology is adopted to produce hot stamping forming steel with the tensile strength being 1800 MPa, the mechanical property is ensured, the plate roll repeated heating, uncoiling and other procedures in the production process are reduced, cold rolling and annealing heat treatment procedures are omitted, and production cost is reduced.

Description

technical field [0001] The invention relates to a steel for automobile parts and a production method, which precisely belongs to the hot-formed steel with a tensile strength ≥ 1800 MPa produced by an ESP production line and the method. Background technique [0002] With the increasing environmental problems, automobile lightweight has become the core issue in today's automobile manufacturing field. The use of high-strength steel for lightweight design of automobile bodies is the best way to meet the needs of automobile lightweight and improve collision safety. However, at present, for the production of ultra-high-strength steel above 1000MPa, steel companies must use specialized ultra-high-strength steel equipment for production; at the same time, automobile companies have technical problems such as difficult control of stamping springback and poor dimensional accuracy. . [0003] The birth of hot stamping forming technology has solved the above problems well. The hot sta...

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Problems solved by technology

[0008] The present invention aims to overcome the shortcomings of the existing technology such as complex process, high energy consumption and low production efficiency, and provides an ESP production line that can reduce production links, reduce energy consumption, and shorten the production cycle under the premise of ensuring the strength level. Produced hot-formed steel with tensile strength ≥ 1800MPa and method

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