摘要
某公司生产的钻杆接头外螺纹在加工时出现裂纹,采用显微组织观察对开裂原因进行了分析。结果表明:该接头外螺纹开裂的主要原因是碳化物的聚集偏析造成锻造过程中偏析区产生组织过热现象,碳化物尖端和基体的结合部位由于热应力和机械应力产生的应力集中而萌生裂纹源,并在随后的变形过程中形成裂纹导致开裂。
The cracks were found during machining the external threads of some fillet of tool joint pins. Microstructure observation was used to analyze the cracking cause. The results show that the main cracking reason was that the precipitation of carbides caused microstructure overheating in the precipitation during forging. The cracks generated in the bonding position between tops of carbides and matrix resulting from the stress concentration of heat stress and machining stress, and then formed cracks during deformation.
出处
《机械工程材料》
CAS
CSCD
北大核心
2010年第6期83-84,88,共3页
Materials For Mechanical Engineering
关键词
螺纹
碳化物
偏析
过热
裂纹
thread
carbide
precipitation
overheating
crack
