In view of welding process

joint condition

crack shape

and facility structure

analyzes the causes for cracking of weld joints of connecting pipes from low-temperature superheater to pendant superheater at a power plant in operation. The results show that weld joints are exposed to stress concentration with coarse HAZ grains while various stresses overlap to create peak stress within the sensitive temperature of reheat cracking. Thus

the peak stress leads to loosening stress and results in cracking. To avoid such problems

a few effective repair procedures and preventive countermeasures are proposed

providing reference for enterprises to prevent and control similar problems.