钢球堵塞引起S30432屏式过热器爆管的失效特征分析

Failure Characteristics Analysis of S30432 Platen Superheater Tube Caused by Steel Ball Blocking

以试运行阶段就发生因钢球堵塞造成过热蠕变爆管的某600MW超超临界锅炉屏式过热器为例,通过宏观检查、尺寸测量、化学成分分析、力学性能分析、金相分析、维氏硬度试验和扫描电镜观察等方法,并与相邻管子进行对比,得出了钢球堵塞引起S30432爆管失效的特征。结果表明:爆口部位的管径、壁厚、蠕变孔洞、蠕变裂纹及老化程度等方面存在明显特征,除爆口部位及弯管部位外的各项试验结果均符合标准对新管的要求,但其材质状态已明显差于相邻管子。

Taking the platen superheater tube burst of a 600 MW ultra supercritical boiler caused by overheating creep due to steel ball blockage in the trial operation stage as an example,through macroscopic inspection,size measurement,chemical composition analysis,mechanical property analysis,metallographic analysis,Vickers hardness test and scanning electron microscope observation,and comparison with adjacent tubes,the characteristics of S30432 tube burst failure caused by steel ball blockage are obtained.The results show that the S30432 platen superheater tube plugged with steel ball in the ball passing test has obvious characteristics in the aspects of pipe diameter,wall thickness,creep holes,creep cracks and aging degree;All the test results of the leaking tube except the bursting port meet the requirements of the standard for new tubes,but its material state is obviously worse than that of adjacent tubes.