Influência do tipo de abrasivo do rebolo e do fluido de corte na retificação plana tangencial do aço inoxidável martensítico VP420

Abstract

In an industrial landscape where there is a growing demand for materials which meet project requirements combined with high performance, low manufacturing costs, and sustainability, stainless steel class is highlighted due specific properties and application. Defined as ironchromium alloys with a minimum percentage of 10,5 % chromium and other alloy elements such as Ni and Mo, stainless steels have different types and one of the most versatile one is martensitic stainless steel VP420, commonly used in cutlery industry, in the manufacture of surgical and high precision instruments, as well as in the manufacture of molds and dies for plastic injection. Therefore, in order to meet the manufacturing demand, it is necessary to employ a machining process capable to ensure tight tolerances combined to high surface quality, such as grinding process. In this sense, the purpose of the research is to investigate the influence of the type of abrasive grinding wheel and coolant on surface and subsurface integrity of the VP420 martensitic stainless steel submitted to peripheral surface grinding process. The input variables employed were: two types of abrasive wheels (monocrystalline aluminum oxide and conventional white aluminum oxide), two types of cutting fluids (synthetic and semi-synthetic) and two depth of cut values, ae (10 µm and 25 µm). The output parameters were to the surface roughness parameters Ra, Rt and Rz surface images (SEM) and Vickers microhardness of the machined surfaces, as well as grinding power. Results showed that grinding with combination between monocrystalline aluminum oxide grinding wheel and synthetic coolant, at ae = 10 µm, provided the lowest values of roughness, microhardness and grinding power. However, when the same grinding wheel was employed with the semi synthetic fluid and ae = 25 µm, the worse surface texture, that adversely affected the surface roughness, the highest variation in microhardness and lower grinding power.