Ultrasonic Testing for the Hardened Layer Depth of Induction Quenched 20CrMo Axle

Abstract

The interface between the surface hardened layer and the base layer would produce while the 20CrMo axis is treated with high frequency induction quenching method; therefore, the hardened case depth can be measured by high frequency ultrasonic wave based on the echo technique. The test results compared with those from the metallographic method show good qualitative agreements.