FRICTION AND WEAR CHARACTERISTICS OF -HIGH CARBON STEEL

Abstract

Due to immense potential of High Carbon Steel in the making of tool and die and machine component. It is very important to know the friction and wear aspect of high carbon steel. In the present work a plain high carbon steel having 0.56 %C has been selected for friction and wear studies. The lamellar pearlite morphology (alternate plate of ferrite and cementite) has been changed to martensite in order to increase the kinetics of spheroidizing heat treatment. Steel samples have been made first martensite by quenching them into water from austenite phase This quenched steel is reheated up to 700`C for different length of time viz 8hr, lOhr ,12 hr . This route of spheroidizing heat treatment gives faster kinetics as compare to heating (ferrite +pearlite) directly at 700L for different length of time. Friction and wear behavior of as received steel and spheroidized steels, having soaking-.time of 8hr, 10hr, & l2hr have been studied at normal load of lkg, 2kg, 3kg & 4kg and at a fix sliding speed of 1.25 m/s. A pin on disc machine was used for friction and wear studies, Weight loss method was used to measure the wear volume for different sliding distance. It has been observed in the present work that by spheroidizing steel the wear volume of the steel increases as compared to as received steel for a given sliding distance and at a normal load. It is further observed by increasing soaking time for spheroidizing annealing increased wear volume is observed as compared to received steel For example maximum wear increased volume is observed as compared to steel sample which has undergone l2hr soaking for annealing. Friction coefficient has been found to decrease in spheroidized specimens as compare to as received specimen. 12 hr duration spheroidized specimen has shown lowest coefficient of friction 0.4. It is further observed that for a given spheroidized sample increase in normal load causes decrease in coefficient of friction. This decrease in coefficient of friction and Increase in wear volume as compare to as received steel have been explained on basis of hardness of steel. In the spheroidized steels, sample soft ferrite phase is actually found to be responsible for decrease in coefficient of friction and increase in wear volume.