Enhancement of Wear Resistance of AISI D2 Steel Slitter using Deep Cryogenic Treatment

Abstract

The cooling of material below-150C for sufficient soaking period is termed as deep cryogenic treatment (DCT). There is an improvement in wear resistance and hardness of tool and die steels due to deep cryogenic treatment. The improvement in wear resistance is observed due to precipitation of fine secondary carbides and even distribution of carbides. In present study, the slitters of AISI D2 cold work air hardening type tool steel are subjected to vacuum hardening followed by deep cryogenic treatment at-185C with samples hold for 36 Hrs soaking period. The slitter is one of the commonly used part in slit rolling mills. The slitter is the solid circular reel having taper cutting edge on its periphery to slit bars into two halves. So, when material got slitted/teared, due to continuous sliding of bar on taper cutting edges of slitter it worn out, due to that replacement has to be done. The improvement in wear resistance was determined by conducting pin on disc wear test on samples taken from slitters. The improvement in hardness has also been observed up to 3 HRc. The slitters are also subjected to the actual running conditions at shop floor from which the real time life evaluation is done.