Effect of Cryogenic Treatment on Hardness and Microstructure of W6Mo5Cr4V2 High Speed Steel

Taking W6Mo5Cr4V2 high speed steel as the research object, the performance of high speed steel material were improved by cryogenic technique. The changing rule of the hardness and microstructure of the specimens was studied through the test analysis. Experimental results show that after different cryogenic heat treatment processes, the high speed steel specimen before tempering respectively in the cryogenic temperature-120 ℃, cooling rate of cryogenic temperature to 2℃/min,24 h of cryogenic insulation performance is the best, the hardness and microstructure are achieved best. Through comparison on cryogenic factors significant sexual relationship analysis. It's concluded that the time of heat preservation on high speed steel hardness has most effect, then is followed by cooling rate,tempering times and cryogenic temperature.