Korolev

pp. 26-39

The authors consider necessity of heat treatment after welding circular butts of thick-walled gas pipelines. They analyzed two main welding technologies of fixed butts in gas pipelines – hand arc welding by an electrode with the basic type of coating, and combined welding. The weld root is produced by machine welding with a solid section wire using the STT method; filling and facing layers of the weld are produced by auto-welding with a flux-cored wire in the mixture of shielding gases using M300-C welding heads. Results of the thermal and stress analysis allow to justify elimination of post-weld heat treatment of circular butts.