Evaluating and comparing secondary machining characteristics of wrought and additive manufactured 316L stainless steel

Abstract

This paper is based on evaluating, analysing and comparing the secondary machining characteristics of wrought and additive manufactured 316L Stainless Steel. This paper is an attempt to determine the process efficiency and evaluate the machinability factors which effect the service life. Stainless steel is a historic iron carbon alloy reputed for its high corrosive resistance and extensive application base. Threading, tapping, reaming and knurling are the most common secondary machining operations after a primary machining operation to achieve a required surface finish and form. As threading plays a significant role in fastening two components together. Threading is selected as a secondary machining operation in this paper. The research methodology consists of conducting threading operation on a hollow cylinder of 50 mm diameter using a lathe. Threads are cut into the workpiece using variable cutting parameters such as spindle speed; 90 and 180 rpm and coolant condition; on/off. Thread pitch which is also the feed rate (1 mm/rev) and Depth of Cut (0.3 mm) remains constant for all the trails. Statistical data are collected and analysed by qualitative and quantitative evaluation. The outputs under consideration to evaluate the machinability includes the cutting forces, thread profile accuracy (pitch) and tool wear. It has been observed that the cutting force and the tool wear was predominantly high for SLM compared to wrought. The paper concludes to convey the point that wrought components has better machinability characteristics than additive manufactured stainless steel.