中性子回折法による自動車用高周波焼入れシャフトの残留応力分布測定

抄録

Induction hardening is a surface hardening method that is widely used to improve the fatigue strength of automobile parts. It is difficult to measure the residual stress distribution of induction hardened layer using the conventional X-ray diffraction method. Therefore, there are few reports on the results of measuring the residual stress distribution in the induction hardened parts. Therefore, in this study, we focused on the neutron diffraction method and measured the residual stress distribution of induction-hardened parts using J-PARC BL19. As a result, it was found that the residual stress distribution was almost symmetrical around the center of the test piece. In addition, the residual stress distribution in the axil and hoop directions showed a similar tendency, within the limits hardness range of induction hardening becomes compressive residual stress field, out of range it has been a tensile residual stress field. Furthermore, it was found that the maximum tensile residual stress was generated at a position where the hardness was equal to the internal hardness without the influence of induction hardening.