Stress corrosion processes in the metal and welded joints in gas pipelines

Abstract

Stress corrosion cracks were produced in steels 20, X46 and X70, indicating the complicated mechanism of formation and the existence of several stages of the process taking place with time during contact of the stressed metal of the pipes with the corrosive medium around the pipe. A method and specimens, simulating the working conditions of the actual pipeline, are developed. The results of analysis of the stress corrosion cracks formed in steels 20, X46 and X70 are used to investigate the process of nucleation and propagation of the cracks in relation to the stress state and the corrosive medium.

Keywords::

• gas pipeline
• welded joints
• stress-corrosive crack