FAILURE ANALYSIS OF STAINLESS STEEL BELLOWS USED IN HEATING PIPELINE
热力管线中不锈钢波纹管破裂原因分析

The failure analysis of the 304 stainless steel bellows used in heating pipeline has been conducted by using optical microscope and scanning electron microscope(SEM).The results showed that the cracking features of the bellows were different from the normal circumferential cracking.The cracks of the bellows propagated axially with the typical transgranullar stress corrosion cracking features.The cracking was induced by the chlorides in soil.The circumferential working stress may play a dominant role and the residual stress due to cold working were also responsible for the cracking.