SPCC鋼板を母材とするレーザ溶接継手の散逸エネルギに基づく疲労強度評価

抄録

Laser welding has many advantages, such as the ability to achieve high-quality welds with low deformation, but it has been confirmed that welding defects occur depending on the welding conditions. The welding defects are likely to be the initiation point of damage, it is necessary to optimize the welding conditions and evaluate the fatigue characteristics to ensure the safety and reliability of welding joint. This study focused on evaluation of fatigue strength based on dissipated energy. This evaluation method can evaluate the fatigue strength in a short period of time. So, this study investigated the applicability of this evaluation method to laser welding joint by SPCC. As a result, evaluation of fatigue strength based on dissipated energy of SPCC base metal and laser welding joint was realized, and it was clarified that evaluation of fatigue property based on dissipated energy for laser welding joint was effective. The fatigue fracture origin of laser welding joint was the area of base metal, and it is found that the fatigue strength in the welded area is higher than that in the area of the base metal. As a result of evaluating the fatigue strength of the laser welding joint based on the dissipated energy, it is found that the fatigue strength of the laser welding joint is almost the same as the fatigue limit obtained from the fatigue test.