60Si2CrV钢坯角部横向裂纹的研究

Research on Transverse Crack of 60Si2CrV Billet Corner

摘要

针对60Si2CrV钢坯角部横向裂纹问题，通过经宏观观察、测量，低倍检验、金相分析、扫描电镜等方法进行分析，研究了钢坯角部横向裂纹形成的原因。结果表明，60Si2CrV钢坯存在菱变现象，在四角的冷却存在冷却不均问题，裂纹为穿晶断裂，应是温度偏低时塑性不足，在拉应力作用下形成开裂。裂纹除近表面和裂纹末端存在脱碳外，大部分没有脱碳，也说明裂纹形成温度相对较低。缺陷部位集中在内弧锐角，有可能是锐角温降更快速，在拉矫过程中内弧受拉应力而形成拉裂。

Abstract

Aiming at the transverse crack in the corner of 60Si2CrV steel billet, the causes of transverse crack in the corner of steel billet were studied by macroscopic observation, measurement, low power test, metallographic analysis and scanning electron microscopy. The results show that the 60Si2CrV billet has the phenomenon of diamond deformation, the problem of uneven cooling at four corners, and the crack is transcrystalline fracture, which should be due to insufficient plasticity at low temperature and cracking under the action of tensile stress. Most of the cracks did not decarburize except near the surface and crack end, which also indicated that the crack formation temperature was relatively low. The defect parts are concentrated in the acute angle of the inner arc, which may be because the temperature drop of the acute Angle is faster, and the inner arc is subjected to tension stress in the process of tension correction.

关键词

钢坯 / 60Si2CrV / 角部横向裂纹

Key words

billet / 60 Si₂CrV / transverse corner crack

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