STUDIES ON FRICTION AND WEAR OF MALLEABLE CAST IRON

Abstract

In the present work an attempt has been made to reduce the time of malleablising heat treatment cycle. Instead of using pearlite plus transformed ledeburite structure in as received white cast iron, martensite plus cementite structure has been produced in white cast iron by quenching heat treatment. This quenched white cast iron has been reheated to 950°C for three hours for first stage of graphitization followed by furnace cooling. Microstructure, hardness values and possible reasons for the reduced time of malleablising heat treatment cycle have been discussed. The need to minimize both material and energy loss in mechanical systems has led to an enlarged interest in the field of "Tribology" the science of friction, lubrication and wear. The aim of the present investigation is to analyze wear behavior of malleable cast iron in contest of its mechanical properties and microstructure and to find out the value of Archard's coefficient. In view of the above, wear test has been done on pin-on disc testing machine at different loads (9.81, 14.71, & 19.62N) and at constant speed of 1 m/s for as-received,3 hours annealing, 4 hours annealing, and 5 hours annealing samples. It is observed that with increase in load and sliding distance, wear volume is observed to increase continuously. To understand the wear mechanism, wear tracks and wear compact layer have been studied under scanning electron microscope (SEM).