Fatigue Fracture, CTOD, and CVN Testing in Heat-Affected Zone of High Strength Low Alloy Steels

Abstract

High strength low alloy steels (HSLA) are currently used in large quantities for constructions in the North Sea and elsewhere. For success operation under such rigorous conditions, it is essential to ensure adequate weld metal toughness at temperatures of -10ºC or even lower is used. To comply with this high requirement, the heat input control is needed to avoid forming martensitic microstructure in high strength low alloy steels (HAZ) near to the fusion line during weldment cooling. This work carried out CTOD tests to ensure that, under welding conditions, the fatigue crack, toughness, hardness, and resilience in the HAZ are acceptable with the standards. Crack size in accordance with number cycles will be represented as the crack growth rate da/dN vs. stress intensity factor amplitude.