Development of cold-rolled 800 MPa grade high strength low alloy steel for automobile

doi:10.13251/j.issn.0254-6051.2021.01.023

Abstract

Abstract: Cold-rolled 800 MPa low alloy high strength steel with good ductility and formability was developed by means of C-Si-Mn-Nb-Ti-Cr-Mo chemical composition design and key production process parameters control.The results show that the microstructure of the tested steel is composed of ferrite,martensite and a small amount of bainite.The second phase particles and carbide precipitation phases are dispersed in the ferrite matrix.The yield strength of the tested steel is more than 800 MPa,the elongation is more than 10.5%,the difference between tensile strength and yield strength is less than 35 MPa,the hole expansion rate is more than 56.5%,and there is no visible crack on the 180° cold bending test,which showing good formability.

Key words: high strength low alloy(HSLA), continuous annealing, microstructure and properties, precipitates, formability

CLC Number:

TG142.1

Wang Keqiang, Liu Rendong, Guo Jinyu, Fu Wei, Huang Qiuju, Sun Rongsheng. Development of cold-rolled 800 MPa grade high strength low alloy steel for automobile[J]. Heat Treatment of Metals, 2021, 46(1): 120-124.

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