HT250灰铸铁曳引机底座断裂分析  

Fracture Analysis of HT250 Gray Cast Iron Traction Machine Base

作　　者：陈桂丰 周崎 李浩 龙赛琼 Chen Guifeng;Zhou Qi;Li Hao;Long Saiqiong(Guangzhou Customs District Technology Center,Guangzhou 510623,China)

机构地区：[1]广州海关技术中心,广州510623

出　　处：《机电工程技术》2021年第6期268-269,282,共3页Mechanical & Electrical Engineering Technology

基　　金：国家重点研发计划项目(编号:2018YFF0215502)。

摘　　要：某公司在测试灰铸铁曳引机底座铸造新工艺时,发现同批次中有多个底座出现裂纹。为找出开裂原因,提高产品质量,对问题曳引机底座采用断口分析、化学成分、硬度检测等手段进行分析。结果表明:机壳裂纹属于铸造应力引起的冷裂,裂纹源区位于底座壳体敞口壁厚转变处,属于应力集中位置,从金相组织上可以看出,源区存在强烈的沿枝晶排列的石墨组织及枝晶柱状分布的共晶碳化物,加速裂纹扩展。When testing the new casting process of gray cast iron motor base,several cracks were found in the same batch.In order to find out the cause of cracking and improve the product quality,fracture analysis,chemical composition,hardness test and other means were used to analyze the problem motor base.The results show that the shell cracks are caused by casting stress,and the crack source area is located at the change of open wall thickness of base shell,which belongs to the position of stress concentration.It can be seen from the metallographic structure that there are strong graphite structure arranged along dendrite and eutectic carbide distributed in dendrite columnar distribution in the source area,which accelerates the crack growth.

关 键 词：灰铸铁 铸造应力 冷裂 枝晶排列石墨组织 

分 类 号：TG245[金属学及工艺—铸造]