摘要
某汽车用U型螺栓制成后在搬动过程中发生断裂,断裂位于U型螺栓感应加热的锻打弯曲部位。通过宏观观察、扫描电镜微观观察以及金相检验等方法对螺栓的断裂原因进行了分析。结果表明:由于该U型螺栓锻打弯曲部位感应加热温度过高导致局部过烧,使其在锻打应力的作用下沿晶开裂形成热裂纹;冷却后该裂纹在搬动过程中的低应力作用下扩展导致螺栓最终脆断。
U shape bolts using for automobile fractured during transport process. The fracture position was located at the forged and bended part. The fractured bolt was researched by macroscopic and microcopic analysis. The results show that over burning happened because of the too high inductive heating temperature and hot crack formed by stresed. Finally after cooling the crack extended under low stress and led to the fracture.
出处
《理化检验（物理分册）》
CAS
2010年第6期403-405,408,共4页
Physical Testing and Chemical Analysis(Part A:Physical Testing)
关键词
U型螺栓
感应加热
过烧
热裂纹
U shape bolt
induction heating
overburning
hot crack
