Machinability of stainless steel alloys

Abstract

The present work investigates dry milling of AISI 409 Ferritic, AISI 304L Austenitic and AISI 410 Martensitic Stainless Steel with focus on the influence of different parameters such as cutting speed, feed rate and depth of cut on the surface roughness, cutting forces, burr formation and chip formation. A great emphasis is put on the materials interactions with the machining process. For these machining tests, specimens were machined under different cutting parameters using the same tool in order to develop a global approach to predict the machining behaviour (surface roughness, forces, burr and chip formation). The results showed that the surface roughness increases with the increase of the feed rate and the cutting speed. It was also found that there exist a relationship between the material hardness and surface roughness. The cutting speed was found to have a considerable and clear impact on cutting force. Differences observed in chip morphology were linked to the changes in workpiece hardness. Fewer burrs were observed on the workpiece surface at high cutting speed. It has been found that the material hardness and the cutting speed have a considerable effect on the burr generated. An increase in the cutting speed on harder materials reduces considerably burr and thus improve surface quality. An adequate choice of cutting speed and feed per tooth, allows a favourable tool operating condition with stable and moderate cutting forces in addition to reduced vibrations. Lastly, correlations were established between surface roughness, cutting forces and chip formation. Based on a statistical analysis that takes into account the cutting forces, the workpiece hardness and microstructures, a recommendation on the optimal cutting parameters that favours the machinability of the tested stainless-steel alloys was made.

Date	30 Nov 2018
Original language	American English
Awarding Institution	École de technologie supérieure
Supervisor	Victor Songmene (Supervisor)