Microstructure and strengthening mechanism of a novel 700 MPa grade high strength anchor steel

doi:10.13251/j.issn.0254-6051.2023.05.007

Abstract

Abstract: Microstructure and mechanical properties of a self-designed 700 MPa grade high strength anchor steel were investigated systematically by means of optical microscope, scanning electron microscope as well as transmission electron microscope, etc, and the strengthening mechanisms of the tested steel were further quantitatively discussed. The results show that the microstructure of the tested anchor steel is composed of banded laminated pearlite and fine equiaxed ferrite, the volume fraction of pearlite is about 43%, and in the ferrite there are a large amount of nano-sized V(C, N) precipitated particles (<20 nm). In addition, the tested steel has good comprehensive properties, with the yield strength, tensile strength, and elongation after fracture being respectively about 734 MPa, 936 MPa, and 15.1%, and the yield ratio being about 0.78. The strengthening mechanism of the tested anchor steel is a coupling of grain refining strengthening, solid solution strengthening, dislocation strengthening, and precipitation strengthening, where the contributions induced by grain refining strengthening and solid solution strengthening account for about 73% of the total strength.

Key words: anchor steel, mechanical properties, strengthening mechanism, microstructure

CLC Number:

TG142.4

Meng Yasen, Pan Lifang, Zhang Hongxu, Liu Peng, Ren Zhifeng, Liu Guangming. Microstructure and strengthening mechanism of a novel 700 MPa grade high strength anchor steel[J]. Heat Treatment of Metals, 2023, 48(5): 41-48.

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