Development of technological solutions for producing longitudinal-seam electric-welded pile pipes without bulk heat treatment

Abstract

This study developed technological solutions for producing longitudinal-seam electric-welded pipes without bulk heat treatment to meet the impact toughness requirements for the welded joint, as specified in SP 16.13330.2017. It was established that localized heat treatment only marginally increases the impact toughness of welded joints made from 09G2S steel, primarily due to a degree of microstructural homogenization. The content of non-metallic inclusions in the sheet billet was identified as one of the most critical parameters. Furthermore, optimization of the welding parameters on the pipe welding mill can also enhance the quality and serviceability of joints produced by high-frequency electric resistance welding.