Use of a stepped preparation to improve the damage tolerance of grade 91 steel welds

Damage equivalent to that seen over very long times in Grade 91 steel welded components was successfully formed in laboratory, feature sized samples tested under controlled conditions. This paper compares the creep behaviour of welds made using a typical preparation with results for novel step weld geometries. When well-designed the step geometry offsets the heat affected zone (HAZ) in the through thickness of the weld which would be equivalent...