Improvement in Wear and Friction Properties of Heat-Treated Steel Using Micro-grooved Patterns

Surface wear is one of the leading causes of failures in sheet metal forming dies. Surface wear significantly affects productivity as well as the overall product cost. For forming dies, D2 steel is mostly used. D2 steel is High Carbon High Chromium Steel (HCHCr). In the present work, modern surface modification techniques are investigated to understand their effect on tribological properties such as wear and friction in order to minimize the surface wear failures. Hence Modern surface modification techniques selected are plasma ion nitriding, micro-grooving, and solid lubrication. Plasma ion nitriding is a heat treatment process and carried out in plasma chamber. Micro-grooving was carried out using laser surface texturing. Dimple, rhombus, concentric circular, asterisk, and cross grooves patterns were used for micro-grooving. 5 Samples of D2 steel were prepared using heat treatment (plasma ion nitriding) and micro-grooving (laser surface texturing). Wear and friction coefficient of samples of untreated and treated D2 steel were determined on pin-on-disc Tribometer. Tests were conducted at room temperature with alumina pin (99.99% pure) and D2 steel plate samples with Graphite as a Solid lubricant. The micro-grooves provide storage spaces for graphite, indirectly improves the life of lubricant. Hence micro-grooving and solid lubrication help for effective improvement in the tribological properties. The outcome of this research work is very promising and showed reduction in wear and friction coefficient up to 95% and 80%, respectively, when these modern surface modification techniques are used.