METHODS OF GIRTH WELDING HIGH STRENGTH STEEL PIPES TO ACHIEVE PIPELINE CRACK ARRESTABILITY

摘要

Girth welds (80) with crack arresting capability, and welding methods for producing same in high strength pipelines, are provided. Girth welds (80) according to this invention are produced in high strength pipelines by welding methods that produce (i) HAZ (84) microstructures that are softer than the pipeline steels, (ii) weld toes (81), (83), (85), and (87) that act as stress/strain concentrators, thus promoting tearing in the HAZ (84) and a ring-off fracture; and (iii) a weld geometry that promotes an inclined fracture path.