Fillet welded joints with excellent fatigue crack initiation characteristics

摘要

PPROBLEM TO BE SOLVED: To provide a method for designing a joint excellent in fatigue strength, which improves fatigue crack generation property at a weld toe, and increases the fatigue life of the fillet welded joint obtained by lap fillet welding or fillet boxing welding of a sheet or a plate with a thickness of 1-20 mm. PSOLUTION: In the fillet welded joint made of a steel sheet or a plate which is excellent in fatigue crack generation resistance, when a fusion boundary FL at the weld toe is defined as a base point, the ratio of the hardness Hv(FL-0.5) of the weld metal at a position 0.5 mm apart from the base point toward the weld metal to the hardness Hv(FL+0.5) of the heat-affected zone at a position 0.5 mm apart from the base point toward the heat-affected zone is 0.3 or more and 0.9 or less. PCOPYRIGHT: (C)2008,JPO&INPIT