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.