Kinetics of graphite precipitation during tempering process of a medium-carbon high-silicon high-aluminum steel

doi:10.13251/j.issn.0254-6051.2023.10.035

Abstract

Abstract: Microstructure, precipitation behavior and nucleation and growth mechanism of graphite particles during tempering process of a medium-carbon high-silicon high-aluminum steel were systematically studied by means of metallographic microscope, scanning electron microscope and graphite particle growth kinetics equation. The results show that after tempering at 680 ℃ for 2, 5 and 8 h, the total density of graphite particles is 2539, 4791 and 6405 number·mm^-2, respectively, and the corresponding average size of graphite particles is 1.30, 1.80 and 1.90 μm, respectively. During tempering at 680 ℃, the nucleation of graphite particles is mainly at the grain boundary of ferrite, and the critical nucleation size is about 0.6 nm. The growth behavior of graphite particles in ferrite follows the Ostwald ripening rule, and the ripening rate is 29.38 nm·s^-1/3.

Key words: medium-carbon high-silicon high-aluminum steel, tempering, graphite particles, grain boundary nucleation, rate of ripening

CLC Number:

TG142.7

Wan Yong, Ma Dong, Chi Dunwei, Tian Lijie, Liu Mingqi, Wen Yonghong. Kinetics of graphite precipitation during tempering process of a medium-carbon high-silicon high-aluminum steel[J]. Heat Treatment of Metals, 2023, 48(10): 225-230.

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