In thermal power plants, cracks, after alternative stresses, may occur in fillet welding joints of branch tube seats on header because of incorrect structure of the joints or defects in welds, which lead to leakage and causing unplanned outage.

• 在火力发电厂中,联箱与支管管座角焊缝结构不合理或焊缝内部存在缺陷,在交变应力的影响下会产生裂纹,引发泄漏,从而导致机组非计划停运。