시편가공에 의한 SM490A 재질 용접시편의 물성 및 피로거동 영향 연구

초록

This study investigates the effects of the material properties and the fatigue behaviors in the SM 490 A material butt weld specimens due to the heat-treatment and the grinding. Both yield strength and tensile strength of the tensile specimens with the heat-treatment are lower than these of the specimens without the heat-treatment. But there is no effect of grinding in the material properties of all tensile specimens. In the fatigue behavior, the heat-treatment affects the fatigue life. The S-N curves of both matrix specimen and butt weld specimen are reversed at some cycle by the existence or nonexistence of heat-treatment. The grinding on the bead makes the fatigue limit decrease in the all specimens. But the reinforcement removed, the fatigue limit increases at the high cycle.