锚杆杆尾螺纹低应力脆断原因分析

Analysis of Causes for Low Stress Brittle Fracture of Bolt End Thread

通过成品化学成分、力学性能分析、金相组织检验、断口形貌对比分析,并结合杆尾螺纹加工工艺,分析MG600钢筋在滚丝加工螺纹后低应力脆性断裂原因:力学性能偏高,珠光体球团直径较大,使钢筋冷塑性加工性能较差,且杆尾螺纹加工粗糙,在杆尾螺纹处易产生加工硬化和局部应力集中,出现低应力脆断现象。

Combined with the bolt end thread processing technology, through the analysis for chemical composition and mechanical properties of the product, metallographic examination and fracture morphology comparison, analysis of causes was made for low stress brittle fracture ~ff high strength bolt MG600 after screw thread processing. The results show that the higher mechanical properties and larger pearlile pellet diameter cause the poor cold plastic processing performance of the bolt. Due to the rough processing to the bolt end thread, it is easy to produce work hardening and local stress concentration on the bolt end thread, so the low stress brittle fracture phenomenon is easy appear.