论文部分内容阅读
某高压设备进行水压试验前准备,在拧紧螺栓过程中有一螺栓发生断裂,通过对断裂螺栓进行化学成分分析、力学性能试验、金相检验以及断口分析,找出了螺栓的断裂原因。结果表明:由于螺栓原材料在切除冒口时切除量不够,使螺栓中存在较多的夹杂物,夹杂物容易导致应力集中并萌生微裂纹,在螺栓后续加工过程中受到力(拉拔应力和热处理内应力)作用时,裂纹不断扩展并形成空洞,从而导致螺栓在拧紧过程中施加较小的外力就发生了断裂。
A high-pressure equipment hydrostatic test preparation, tightening the bolt in the process of a bolt fracture, fracture of the bolt by chemical composition analysis, mechanical properties test, metallographic examination and fracture analysis to identify the cause of the bolt fracture. The results show that there are many inclusions in the bolt due to the insufficient removal of raw material when removing the riser. The inclusions easily lead to stress concentration and germination of micro-cracks, which are affected by the subsequent processing of the bolt (drawing stress and heat treatment Internal stress), the crack expands and forms a cavity, causing the bolt to break when a small external force is applied during the tightening process.