Study of sub-zero treated and coated gauge and tool materials

Wear rate of materials used in the manufacture of tools and inspection gauges is an important parameter. Pin on disc tribological tests are conducted on three different grades of material which includes HSS M2, OHNS and D2 Grde. Three sets of pin-on-disc samples of standard size for the three grades of materials, namely HSS M2 grade, OHNS and D2 grade, were prepared. All sets of samples underwent conventional heat treatment. The first set of conventional heat-treated samples was analyzed as heat treated samples, the second set of samples was given sub-zero treatment and the third set of samples were coated with TiN using the PVD coating method. Specimens of the three sets were used for finding the wear rate on a pin-on-disc tribometer. The distance of sliding was 3000 mm at a load of 50N and velocity of sliding of 3.0 m/s. A consistent wear rate reduction was observed in D2 steel after heat treatment, sub zero treatment and coating. HSS M2 wear rate on coated samples is the lowest, while coated OHNS steel samples exhibit the maximum wear rate. Mass loss is lowered in the wear test by 66.67% in coated HSSM2 steel and 50% lowered mass loss in coated D2 steel compared to sub-zero treated specimens.