Failure Reasons for 20G/316L Double Metal Composite Pipe

In order to ascertain the failure reasons for the 20G/316L bimetallic composite pipe used in a domestic gas field, the failure morphology of the samples was analyzed and the welding process was simulated with ANSYS. It was found that the lower part of the pipe near the starting point of the weld was seriously corroded, and pitting was the main corrosion form, and the welding stress played a significant role in promoting and inducing the failure. The failure reasons of 20G/316L bimetallic composite pipe were welding stress, Cl- and galvanic corrosion.