通过对某热电厂开裂失效的炉管进行宏观检验、化学成分分析、力学性能试验、金相检验等分析, 确认了引起炉管开裂的原因。结果表明: 炉管开裂主要是由于高温环境长期运行导致炉管材料发生蠕变, 力学性能下降所致。建议应根据规范要求采取加强炉管服役期间检修时的监测工作, 按规范要求在锅炉高温部位设置蠕胀监测点, 将炉管的服役期控制在总的相对蠕变应变小于2%之内, 以保证锅炉的正常安全运行。

By means of macroscopic examination, chemical compositions analysis, mechanical properties test and metallographic examination, cracking reasons of the furnace tube of a thermal plant were analyzed. The results show long-term operation at high temperature resulted in the occurrence of creep, decrease of mechanical properties and cracking of the furnace tube. It was suggested to strengthen monitoring work to the furnace tubes during their service and repairing process, set creep bulge control point at high temperature positions of the boiler, and control the enlistment of the furnace tubes with relative creep rate being less than 2% to insure the normal and safe operation of the boiler.