Cold-rolled CP980 steel with different yield strength grades and production method thereof

Abstract

The invention relates to a cold-rolled CP980 steel with different yield strength grades and a production method thereof. The method comprises a billet heating process, a hot rolling procedure, an acidrolling procedure, a continuous annealing and leveling procedure, and through reasonable component design and effectively controlling key process parameters of each process section, the cold rolled CP980 steel products with two yield strength grades of 770-840 MPa and 860-930 MPa can be produced by using a component system, steel product which has the yield strength grade of 770-840 MPa has hightensile strength and good plasticity, and is particularly suitable for safety part manufacturing which requires 980 MPa grade and has good impact resistance; the steel product which has the yield strength grade of 860-930 MPa has high yield strength and tensile strength, good extensibility and excellent reaming performance, and is particularly suitable for manufacturing complex automobile parts requiring 980 MPa grade and has special requirements such as flanging, reaming.

Description

technical field [0001] The invention belongs to the technical field of advanced high-strength steel materials for automobiles, and specifically relates to a cold-rolled CP980 steel with different yield strength levels and a production method thereof. Background technique [0002] With the continuous improvement of energy saving and emission reduction as well as economical and safety requirements, the modern automobile manufacturing concept proposes multi-performance, multi-part, multi- different requirements for specifications. High-strength CP steel has good ductility, anti-collision absorption capacity and residual deformation, and its rational application is of great significance to realize the lightweight of automobiles and improve safety. [0003] However, the cold-rolled CP980 steel products for automobiles have the characteristics of multiple parts, diversified performance requirements, multiple specifications, and special needs for small batch orders, which bring a ...

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Problems solved by technology

For example, the patent of publication number CN 107557695A provides a method for controlling the acid rolling production process of CP980MPa multiphase steel, but does not provide a complete preparation method and the final performance index of CP980 steel; publication number CN 103131946A provides a low-carbon phosphorus-containing Cold-rolled multiphase steel and its preparation method, the tensile strength can reach more than 840MPa, and the elongation at break can reach more than 12%, but the yield strength index is not disclosed; the patent of publication number CN 103045941A provides a high-strength toughness multiphase steel and Its heat treatment method has a yield strength of 802-922MPa; the patent publication number CN 107227432A provides a high-strength toughness nano-scale composite steel and its preparation method, and the yield strength is 1311-1402MPa; and the present invention provides a method for producing different yield strength grades The method of cold rolling CP980 steel, the product thickness specification range is 0.80-2.00mm, including two yield strength levels of 770-840 and 860-930MPa

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