| 摘要 |
PURPOSE:To provide a quench hardened layer depth measuring method applicable to a work having the free-shape surface and capable of easily measuring the depth of a quench hardened layer at an accurate measurement position in the cross direction. CONSTITUTION:A longitudinal ultrasonic wave is transmitted into a quench hardened layer W1 from the surface while displacing a focal point in depth with a high frequency probe 2, and a surface reflected wave S from the surface and a boundary reflected wave R from a boundary B between a base material W0 and the quench hardened layer W1 are received by the high frequency probe 2. A relationship between the strength and the propagation time of the surface reflected wave S and the boundary reflected wave R is found and the depth of the quench hardened layer W1 from the surface is found from a difference between the propagation time of the surface-reflected wave and the propagation time of the boundary-reflected wave. |
