摘要
通过成分分析、低倍观察、金相分析、硬度检测及Z向拉伸等手段分析厚度为35 mm的40Cr热轧板调质开裂原因。结果表明,40Cr热轧板中部存在由亮带和暗带组成的宽为12 mm的偏析带原始缺陷,经调质处理后,基体及亮带区域内回火索氏体组织中分布有显著的块状及条状铁素体,而暗带组织为较均匀的索氏体。界面两侧存在的机械性能差异导致该区域成为了材料的薄弱地带,在淬火的快速冷却应力作用下形成应力集中,从而产生沿偏析带方扩展的7.8 mm深淬火裂纹。
By means of composition analysis, low-powered observation, metallographic analysis, hardness test and Z-direction stretching, the quenching and tempering cracking causes of 35 mm thick 40 Cr hot rolled plate were analyzed. The results showed that the original defect of 12 mm wide segregation band composed of bright bands and dark band exists in the middle of 40 Cr hot rolled plate. After quenching and tempering, there are obvious massive or strip ferrite in tempered sorbite in matrix and bright band. The dark zone is composed of homogeneous sorbite. The difference of mechanical properties between the two sides of the interface leads to the weak zone of the material. The stress concentration is formed under the rapid cooling stress of quenching,which leads to the 7.8 mm deep quenching crack extending along the segregation zone.
作者
顾杰
周传昆
闫明
陆凯雷
顾志斌
GU Jie;ZHOU Chuankun;YAN Ming;LU Kailei;GU Zhibing(NR Electric Power Electronics Co.,Ltd.,Changzhou 213025)
出处
《现代制造技术与装备》
2022年第1期154-156,共3页
Modern Manufacturing Technology and Equipment
关键词
40Cr
热轧板
偏析带
调质开裂
40Cr
hot rolled plate
segregation zone
quenching and tempering cracking
