Effect of Shot Peening Parameters and Heat Treatment Schedules on Microstructures and Wear Behaviour of Medium Carbon Steel

Abstract

The mechanical properties of medium carbon steel change with its microstructure. The microstructure can be varied through heat-treatment and thermo-mechanical behavior. In agricultural sectors, plain carbon steels are largely used because of their low cost, easy to treatment of heat and deformation. The wear characteristic of a material is a surface phenomenon. Thus, the wear rate of a metallic material can be reduced by surface modification either through chemical heat treatment, surface coating with hard-facing and ceramic materials and surface hardening. Shot peening is a process during which fine shots are peened on the surface of component at high impact speed which lead to remaining compressive stresses inside the material s exterior surface plus also refine the surface microstructure. Also, the exterior surface has been subjected to plastic deformation which causes surface work-hardening. The resistance for wear is also an application of surface characteristics like micro-crack formation, dent size formation due to peening, and surface remaining stress. The range of peening can be defined as peening intensity. Earlier it was observed that irrespective of heat treatment schedules, the intensity of peening of 0.27 A, is the optimum to achieve the highest wear resistance. For same peening intensity, the pressure of peening and size of shots can also vary. Depending on the size of shots, the size of dents will also vary. Even individual impact energy will also vary. Again, with the peening pressure variation, interaction between input shots and rebounding of shots increases. Thus, there might have an alternation of surface characteristics like residual stress state, workhardening, surface microcracks and subsurface microstructures, with the change of shot size and peening pressure. In the attentive investigation, many attempts have been adopted to inspect the consequence of heat treatment on the microstructures, automatic properties and low stress abrasive wear resistance.