Experimental Analysis by Measurement of Surface Roughness Variations in Turning Process of Duplex Stainless Steel

Abstract

Abstract The objective of the investigation was to identify surface roughness after turning with wedges of coated sintered carbide. The investigation included predic ting the average surface roughness in the dry machining of Duplex Stainless Steel (DSS) and the determination of load curves together with roughness profiles for various cutting conditions. The load curves and roughness profiles for various cutting wedges and variable cutting parameters were compared. It has been shown that dry cutting leads to a decrease in friction for lubricated surfaces, providing a small initial contact area where the surface is contacted. The st udy has been performed within a production facility during the production of electric motor parts and deep-well pumps. Keywords: turning, coatings, friction-reducing, optical microscopy, surface roughness analysis and models. © 2014 Polish Academy of Sciences. All rights reserved 1. Introduction Engineering surfaces, particularly those generated using multi-step manufacturing processes and intended for tribological applications such as bearings and gears, rarely if ever have perfectly normal distributed elevations [1]. Surface roughness measurements of any workpiece are among the most important ones in length and angle metrology, both in theory and practice. According to Wieczorowski et al. [2], there are great discrepancies in these measurements because of the large variety of instruments for surface roughness analysis. Hence, three-dimensional surface topography parameters are necessary for assessing the surface roughness characteristics more effectively [3]. According to Mahovic Poljacek et al. [4], a precise characterization of roughness and surface topography is of prime importance in many engineering industries because certain functional properties of the materials are often determined by the surface structure and characteristics. Estimation of the magnitude of surface roughness under the given cutting conditions resulting from metal removal operations is one of the major goals in this area [5, 6]. According to Benardos and Vosniakos [7], surface roughness is a widely used index of product quality and in most cases a technical requirement for mechanical products. Achieving the desired surface quality is of great importance for the functional behaviour of a part. Surface profilometry is for many years a well-known method of topography inspection [8–12]. Topography parameters represent surface properties is much better than 2D ones. Using the surface parameters can be determined functions describing surface behaviour. The workpiece material is duplex stainless steel because this stainless steel is widely used for many industrial applications due to its unique properties. Cabrera et al. [13] and Park et al. [14] consider that the good combination of their mechanical properties (high strength and toughness) and corrosion resistance makes them of great interest for a wide range of