The Effect on Carburizing Process on Microstructure and Properties of 20MnCr5 Gear Steel

In this report, 20MnCr5 gear is characterized and analyzed under two carburizing heat treatment processes by optical microscope (OM) analysis, scanning electron microscope (SEM) analysis, X-ray diffraction (XRD) and Vickers hardness test. Results show that spherical and angular carbides can be obtained by a high concentration carburizing process for 20MnCr5 gear. Reheating and subsequent low-temperature tempering help refine the grains of the infiltration layer, reduce the residual austenite content in the permeable layer, and increase the thickness of the effective hardening layer.