Avaliação da integridade da superfície do aço inoxidável ABNT 316 M após a retificação em diversas condições de corte

Abstract

Grinding is an abrasion machining process that stands out for the metal-mechanical industry, mainly because it is the first option to ensure combination of good surface finish and tight dimensional deviation. Stainless steel plays a major role for the industry, once it has a wide application in mechanical components in modern society that require high corrosion resistance that makes it suitable for applications in more severe conditions of use and high durability such as cellulose processing equipment, steamrollers in the textile industry and tanks from the chemical industry. However, some of stainless steels proprieties such, as low thermal conductivity and high work hardening during machining, reduces its machinability in comparison with hardened steels. Besides, it is known from literature that wrong selection of cutting conditions can adversely affects surface integrity of a component, causing problems such as grinding burn, hardness drop or rise and some metallurgical alterations that may affect its functionality. Since several components from metal working industry generally are subjected to grinding stage to achieve geometric tolerances (for instance the surface roughness) and dimensional ones from a project, such as cutlery items and injection mold parts, for example, it is important to determine proper grinding conditions and provide data for industry to use as a reference. Into this context, this work aims to evaluate the surface integrity of the of 316 M austenitic stainless steel after peripheral surface grinding under different cutting conditions with radial depth of cut of 10 µm and 30 µm, and workspeed of 2.7 m/min and 7.5 m/min. Surface roughness, images from the ground surfaces and microhardness of workpiece were the output variables analyzed. The results showed that surface integrity was adversely affected by the increase in depth of cut and workspeed. Increase of hardness next to the machined surface was recorded after grinding under severest cutting conditions.