Microstructure and properties of bainitic alloy steels with different carbon contents after austempering

doi:10.13251/j.issn.0254-6051.2023.01.009

Abstract

Abstract: Effect of carbon content on microstructure transformation and mechanical properties of bainitic steels with different carbon contents (0.22C, 0.34C and 0.45C) was studied after austenitizing at 960 ℃ and then austempering at above Ms point 10-50 ℃. The results show that the carbide-free bainite microstructure composing of bainite ferrite and retained austenite is obtained after austempering. With the decrease of carbon content, the bainite transformation time is significantly shortened, the bainitic ferrite laths become thicker, and the hardness and tensile strength show a downward trend, while the impact property is obviously improved, which is mainly related to the higher bainite transformation temperture of the low carbon steel, the thick bainitic ferrite laths and the decrease of high carbon blocky retained austenite.

Key words: bainitic steel, carbon content, carbide-free bainite, mechanical properties, retained austenite

CLC Number:

TG142

Hao Xiaoge, Zhao Leijie, Wang Yanhui, Ma Penghui, Zhang Zi, Yue Yun, Xiong Peng. Microstructure and properties of bainitic alloy steels with different carbon contents after austempering[J]. Heat Treatment of Metals, 2023, 48(1): 46-51.

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