Failure analysis of handhole flange cracking

A failure analysis was performed on a cracked handhole flange. Through the analysis of the macro morphology and microstructure of the crack, the metallographic analysis, the mechanical properties test, the chemical compositions analysis of flange material, and the energy spectrum test, the main reason for the cracking can be described as liquation crack, and the failure was aggravated by the sensitization of flange materials. Conclusions and corresponding preventive measures were put forward.