Effect of quenching temperature on microstructure and properties of ultrafine-grained Q&P steel

doi:10.13251/j.issn.0254-6051.2022.12.011

Abstract

Abstract: Effect of quenching temperature on microstructure, element distribution, retained austenite volume fraction and mechanical properties of ultrafine-grained Q&P steels was investigated. The results show that when the annealing temperature increases, the ferrite content gradually decreases, the martensite content increases, and the retained austenite content increases first and then decreases; and at high quenching temperatures, the diffusion rate of C atoms is accelerated, the mechanical stability of retained austenite is better. The presence of soft-phase ferrite provides good toughness for the tested steel. When the quenching temperature is 820 ℃, the comprehensive mechanical properties of the Q&P steel are the best, the tensile strength is 863 MPa, the elongation is 26.1 %, and the strength-plasticity product is 22.5 GPa·%.

Key words: Q&P steel, microstructure, mechanical properties, retained austenite, TRIP effect

CLC Number:

TG161

Guo Haodong, Tang Zhengyou, Zhao Li, Guan Guofu, You Zeyu, Ding Hua. Effect of quenching temperature on microstructure and properties of ultrafine-grained Q&P steel[J]. Heat Treatment of Metals, 2022, 47(12): 67-73.

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