摘要
ML40Cr盘条冷镦螺母侧面出现横向裂纹,螺母金相组织、显微硬度的检测表明材料表面增碳是造成横向裂纹的主要原因。表面增碳层产生于线材球化退火过程,增碳层导致表面硬度升高、塑性降低。利用SOLIDWORKS和Deform-3D软件对螺母的成型过程进行建模和有限元分析,得到螺母在成型过程中的应力、应变及破断指数分布规律。螺母成型过程中心部金属向四周流动,侧面及棱角处会在中间区域产生较大的应力和应变,由于表面增碳层的形成,导致这个区域出现裂纹,从形变的角度解释了螺母产生横裂纹的原因。
Transverse cracks appear on the side of the cold heading nut made of ML40 Cr wire rod. The detection of microstructure and micro hardness shows that recarburized layer on the surface of the material is the main cause of the transverse cracks. Surface recarburized layer forms during spherical annealing of the wire. The recarburized layer leads to an increase in surface hardness and a decrease in plasticity. Using SOLIDWORKS and Demo-3 D software and finite elements analysis to model the molding process of nuts, the stress, the strain and the damage distribution of nuts in the deformation process are obtained. During nut molding process, the metal at the center flows around, and greater stress and strain forms on the boundary of the center and the sides and corners, combined with the formation of recarburized layer on the surface, cracks appeared. This thesis gives an explanation of how transverse cracks of the nuts form from the deformation respective.
作者
李为龙
袁桥军
周国子
LI Weilong;YUAN Qiaojun;ZHOU Guozi(Hunan Valin Xiangtan Iron&Steel Co.,Ltd.,Xiangtan 411101,China)
出处
《金属材料与冶金工程》
CAS
2021年第6期3-7,共5页
Metal Materials and Metallurgy Engineering
关键词
冷镦
螺母
增碳层
横裂纹
有限元分析
cold heading
nut
recarburized layer
transverse crack
finite element analysis
