Influence of Local Properties on Fatigue Crack Growth of Laser Butt Welds in Thin Plates of High-Strength Low-Alloy Steel

In this work, local properties such as hardness and fatigue crack grow rate in the heat-affected zone of four laser-welded butt joints thin high-strength low-alloy steel were examined, so to explain predict lives at high stress levels through fracture mechanics approach. The different welded series presented a similar growth fusion zones, but lower than base metal due higher bainitic–martensitic microstructure verified series. results showed that as-welded condition, initiation stage can be neglected assume some types cracks, with an initial 0.07 mm appropriate rates, estimates life close experimental obtained.