Papers by Keyword: Free-Machining Steel

Abstract: The machinability of an experimental medium-carbon steel with a composition designed to promote rapid graphitisation during a high temperature anneal has been studied. The goal has been to explore alternative routes to a competitive free-cutting composition enabling less expensive steelmaking, manufacturing and recycling. Three starting microstructures prior to annealing have been considered; martensite, bainite and ferrite/pearlite. The microstructures and graphite dispersions formed have been characterised by optical and electron microscopy and the performance of the steel during machining compared with commercial free-cutting steel grades. A bench-top drill rig and metallographic techniques were used to evaluate relative machinability parameters, including surface roughness, tool wear and chip morphology. Thus it proved possible to rank the experimental steel graphitised from the three starting microstructural conditions and also against the commercial free-cutting steels.

Abstract: Surface roughness is a significant aspect of the surface integrity concept. It is efficient to predict the surface roughness in advance by a prediction model. In this study, artificial neural network is used to model the surface roughness in turning of free machining steel 1215. The inputs considered in the prediction ANN model were cutting speed, feed rate and depth of cut, and the output was Ra. Several feed-forward neural networks with different architectures were compared in terms of prediction accuracy, and then the best prediction model, a 3-4-1-1 ANN was capable of predicting Ra with a mean squared error 5.46%, was presented.

Abstract: This paper deals with the mach inability of BN free-machining steel in turning with a supplied current of various values and different directions of electrical current. The tested work pieces were, standard steel AISI 1045 and BN added steel (AISI 1045-BN) based AISI 1045 which has good mach inability at high cutting speed. Turning tests were performed by carbide tool P30 and the power source for additional electrical current supply was a direct current source and the maximum electrical current in the circuit was 20milliamperes (mA). To investigate the influence of electrical conditions of closed circuit system on the cutting mechanism of AISI 1045-BN. The tool life, cutting force, and others were determined experimentally. The testing results show that when turning with carbide tool P30 the maximum crater depth in the tool was reduced drastically when the value of supplied current reached 5mA, regardless of its direction of flow, compared with depths at lower current values; the additional electrical current cutting showed smaller cutting force than those of conditions when turning AISI 1045-BN.