锅炉钢架连接高强度螺栓的断裂原因分析

CAUSE ANALYSIS OF RUPTURE FAILURE FOR HIGH STRENGTH BOLTS USED FOR JOINTING STEEL STRUCTURE OF BOILERS

针对某电厂锅炉钢架连接高强度螺栓的失效断裂,对未安装螺栓和断裂螺栓进行了理化性能检验与分析。结果表明,个体螺栓材料的化学成分、力学性能存在较大差异,加之螺栓不规范安装引起附加弯曲应力,导致了性能较差的螺栓发生延迟断裂。由此,建议对已安装螺栓用小锤敲击法逐个检验,及时更换问题螺栓;对未安装螺栓不同批次不可混用;对整体钢构架进行安全性评定。

Directing against the rupture failure of high strength bolts used for jointing steel structure of boilers in one power plant,inspection and analysis of physico-chemical performance for non-installed bolts and ruptured bolts have been carried out.The results shwo that a large difference exists in chemical components and mechanical property of single bolt materials,morevoer,abnormal installation of bolts leads to additional bendling stress,resulting in delayed rupture of bolts with worse properties.Thereby,it is recommented to inspect the installed bolts one by one by using the small hammer striking method,timely replacing the problematic bolts.For non-installed bolts in different batches,mixed utilization has to be avoided.For an entire steel structure,a safety evaluation has to be carried out.