Microstructure and properties of continuous annealed DP980 high strength steel

doi:10.13251/j.issn.0254-6051.2020.02.008

Abstract

Abstract:

Effect of different technological parameters on the microstructure and mechanical properties of continuous annealed DP980 steel (a 980 MPa grade dual-phase steel) were investigated, with the microstructure and mechanical properties being tested and analyzed by means of optical microscopy, TEM and tensile test. The results show that the microstructure of the annealed DP980 steel is mainly composed of ferrite, martensitic islands and a small amount of bainite, and the dislocation density near the martensite island is higher. With the increase of the over aging temperatures, the tensile strength and yield strength of the DP980 steel first decrease and then increase, and the elongation first increases and then decreases. With the increase of the tempering temperature, the tensile strength and yield strength of the DP980 steel decrease within a small range, while the elongation increases but not obvious, which indicates that adjusting the over aging temperature to regulate the mechanical properties is less effective.

Key words: continuous annealing, dual phase steel, over aging, microstructure, martensite island

CLC Number:

TG166.4

Liu Jingbao, Zhang Hongbo, Geng Zhiyu, Wei Huanjun. Microstructure and properties of continuous annealed DP980 high strength steel[J]. HTM, 2020, 45(2): 42-45.

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