동적 유한요소 해석을 통한 일체형 원자로 안전주입 노즐 이종금속 용접부의 잔류응력에 미치는 레이저 피닝 변수의 영향 고찰

In this study, the effect of the laser peening variable that it reaches to the welding residual stress mitigation through the dynamic finite-element analysis tries to be considered. In case of applying the integrated nuclear reactor safety injection nozzle dissimilar welds in which inner the repair welding is performed to the laser peening, it faced and by using ABAQUS, that is the commercial finite element analysis program, the dynamic finite-element analysis was practiced. Consequently, it confirmed that the tension residual stress at the Alloy 690 series alloy inner surface contacted with the high temperature chemistry primary water was considerably mitigated. In addition, the more the maximum impact pressure, impact pressure duration and laser spot diameter increases, the more the inner surface tension residual stress mitigation decreases, but the more the depth of the mitigated area increases. Also, the laser peening direction can know that an effect is nearly not at the residual stress mitigation.