Cause analysis of pipe explosion of boiler superheater
The pipe explosion of superheater pipeline for a boiler in one self-owned power plant occurred.The exploded pipes and adjacent sections were analyzed by macroscopic inspection,chemical composition,hardness test and metallo-graphic inspection.The results showed that the cracking was due to the long-term high temperature operation of pipes.In addition,the exploded pipes were subjected to overtemperature before explosion.The strength of steel was reduced sharply at high temperature,leading to significant plastic deformation of the pipes.Due to the expansion of the diameter and the thinning of the wall,the rupture and bursting of pipes occurred.The adjacent pipe sections were composed of massive fer-rite and carbide particles with only a few traces of bainite range.After the aggregation and growth of carbides,most of them were granularly distributed at grain boundaries and within grains.The metallographic test results showed that the sphe-roidization grade of the material was 4,and the material had already entered the last stage of life.
high temperature superheaterpipe explosionboiler superheater
万方数据
维普
