INFLUENCE OF MINOR ADDITIONS OF RARE EARTHS AND OTHER ALLOYING ELEMENTS ON THE MICROSTRUCTURE, MACHINABILITY AND MECHANICAL PROPERTIES OF GREY CAST IRON.

Abstract

No data is available for the role played by miech metal on the microstructure, machinability i d mechanical properties of grey cast iron. Though a little qualitative study of the effect of chromium has been made in the past , systematic quantitative data is lacking in the literature an no justifiable conclusion can be drawn out of them. The present investigation has been undertaken with a view to explore the possibility of miseh metal as beneficial alloy addition on the machinability and mechani-cal properties, since India has plenty of its deposLts; and also to find out the quantitative data in chromium alloyed cast irons. The study has been carried out under varying r conditions of cutting speeds, feeds and depths of cut and an attempt has been made to bring a correlation between the various factors to provide the machinists the most optimum practical data for shop use. Machinability has been evaluated in terms of tool life and chip formation. A lathe tool dynamometer has also been developed to measure the cutting forces for evaluating machinability of cast irons treated with much metal.