锅炉螺旋水冷壁T2钢内螺纹管渗漏事故分析

Analysis on Leakage Accident of T2 Internally Ribbed Tube of Spiral Water Wall in Boiler

采用宏观形貌检查、化学成分分析、力学性能测试、金相组织检验及扫描电镜分析等方法,对某660MW超临界燃煤发电机组锅炉中部螺旋水冷壁T2钢内螺纹管的渗漏事故进行分析。结果表明,T2钢内螺纹管渗漏处的线性裂纹是在热轧成荒管时因工艺不当或管坯表面存在缺陷而形成的。建议制造厂加强对热轧荒管表面质量的检查;电厂对同批T2钢内螺纹管端头进行扩大检查,及时发现并消除类似缺陷。

The leakage accident of T2 internally fibbed tube in the middle part of spiral water wall in a 660 MW supercritical units was is analyzed by means of macro examination, chemical composition analysis, mechanical property tests, metallographic examination and scanning electron microscope. The results show that the leakage of T2 internally ribbed tube is due to the linear crack caused by improper hot rolling process of tube billet and the manufacturing defects of tube billet. So it should strengthen the surface quality inspection of hot rolled tube billet in manufactory ; the inspection for the same batch of T2 internally fibbed tubes should be cairried out timely to eliminate similar defects in power plant.