Machinability Studies of Low Alloy Steels by Face Turning Method: An Experimental Investigation

The present study is an experimental investigation on machinability of two low alloy steels, AISI 9320 and AISI 4340, by face turning method. The face turning method makes use of cylindrical steel specimen as a test piece and a triangular P-30 insert as a cutting tool for testing the machinability. The effectiveness of this method is assessed by studying: the cutting time required for the tool to reach flank wear up to 0.3 mm (tool life criterion); tool wear development and wear mechanisms involved in machining; tool life studies and machinability indices of the work-material; surface roughness investigations of the machined surfaces; and chip morphology. The machinability tests undertaken in the current investigation follows some of the guidelines indicated in the international standards, ISO 3685:1993(E) and American Foundry Society (AFS) standard machinability tests. The results presented here demonstrate the ability of the face turning method: to evaluate the tool wear development and tool life studies; to rank the work material according to their machinability, to investigate surface roughness due to tool wear; to investigate chip morphology with crater wear and to characterize the machinability of steels under consideration. The face turning method used here is simple and effective for the given tool-work material pair.