Microstructural and mechanical properties of ultra-high-strength dual-phase steel produced by ultra-fast cooling. Issue 7 (2nd May 2020)

• Record Type: Journal Article
• Authors: Wu, Teng; Wu, Run; Liu, Bin; Liang, Wen; Ke, Deqing
• Is Part Of: Materials science and technology. Volume 36:Issue 7(2020)
• Page Start: 843
• Page End: 851
• Publication Date: 2020-05-02
• Subjects: Hot-rolled DP steel -- ultra-fast cooling -- microstructure -- mechanical property -- work hardening value; Materials science -- Periodicals; Microstructure -- Periodicals; Metallurgy -- Periodicals; 620.1105
• DOI: 10.1080/02670836.2020.1744834
• Languages: English
• ISSNs: 0267-0836

Abstract

ABSTRACT: In the present study, grain refinement of Fe–Si–Mn–Nb–B steel was achieved by high reduction hot rolling. Through the following ultra-fast cooling (UFC) and relaxation process, martensite-ferrite complexes with soft phase embedded in the hard phase were prepared. Extremely tiny ferrite grains significantly increased the toughness of the test steel, a large number of big-angle grain boundaries existing in fine martensite lath bundles effectively improved the strength and the strain hardening ability of the investigated material. The test steel with a relaxation time of 6 s shows the best comprehensive performance with a tensile strength of 1473 MPa, an elongation of 15.0%, a low yield ratio of 0.72 and a product of strength and elongation (PSE) of 22.10 GPa%.