Surface decarburization behavior in microalloyed medium carbon steel for fractured splitting connecting rod

doi:10.13251/j.issn.0254-6051.2025.03.036

Abstract

Abstract: The surface decarburization behavior of 36MnVS4 and 46MnVS5 microalloyed medium carbon steels for fractured splitting connecting rod was carried out by observing metallographic structure and quantitative analyzing decarburized layer. The results show that the surface decarburization behavior of the 36MnVS4 and 46MnVS5 steels heated at 700-1250 ℃ for 60 min is the same. The decarburized layer increases first and then decreases with the increase of heating temperature, with the maximum of 795.4 μm and 898.3 μm at 1200 ℃, respectively. Compared to the 46MnVS5 steel, the 36MnVS4 steel has a lower C content of 0.08% and a higher V content of 0.128%, and the decarbonization sensitivity decreases by 5%-25%. By accelerating the heating speed and cooling speed, or hot forging at the temperature away from the decarbonizing sensitive temperature, the decarburization can be controlled. During heating billets in rolling and forging connecting rod, it's necessary to avoid peak temperatures and reduce residence time.

Key words: microalloyed medium carbon steel, surface decarburization, fractured splitting connecting rod, thermomechanical control process

CLC Number:

TG142.1

An Jinmin, Zhang Yongqi, Lei Sanxiang, Wang Jun, Qu Xiaobo, Zhang Chaolei. Surface decarburization behavior in microalloyed medium carbon steel for fractured splitting connecting rod[J]. Heat Treatment of Metals, 2025, 50(3): 227-231.

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