The influence of grinding wheel type on microhardness and residual stresses in vacuum-carburised 20MnCr5 steel using the single-piece flow method

Abstract

The aim of the experiment described in the paper was to determine the effect of selected conditions of abrasive machining on the size and distribution of microhardness and residual stresses developed in the technological surface layer of flat specimens made of 20MnCr5 steel. The specimens were subjected to single-piece flow low-pressure carburising (LPC) and high-pressure gas quenching (HPGQ) in a 4D Quenching chamber in order to achieve an effective case depth of ECD=0.4 mm. This was followed by grinding the specimens with Quantum and Vortex alumina grinding wheels. Cooling and lubricating fluid were supplied to the grinding zone using the flood (WET) method. The samples were ground in one pass of the grinding wheel using one grinding depth (ae = 0.01 mm). The measurements for each specimen were made twice - after the thermo-chemical treatment and after the grinding. Microhardness and residual stress were measured using the X-ray method sin2Ψ. The final part of the article provides an analysis of the measurement results and presents conclusions and recommendations for further studies.