Cracking reasons of 20G steel boiler flue pipe

The 20G steel boiler flue pipe used in a factory cracked during operation. Macroscopic observation, chemical composition analysis, metallographic examination, mechanical properties test and energy spectrum analysis were used to analyze the reasons for the cracking of the boiler flue pipe. The results show that the enrichment of Cu element and the overheating of the microstructure were the main reasons for the cracking of the boiler flue pipe during operation.