Wear and mechanical properties of carburized AISI 8620 steel produced by powder metallurgy

摘要

The effect of carburization on the tensile strength and wear resistance of AISI 8620 steel produced via powder metallurgy was investigated.Alloys 1 and 2(with 0.2wt%C and 0.25wt%C,respectively)were first pressed at 700 MPa and then sintered at 1300,1400,or 1500℃for 1 h.The ideal sintering temperature of 1400℃was determined.Afterward,Alloys 1 and 2 sintered at 1400℃were carburized at 925℃for 4 h.The microstructure characterization of alloys was performed via optical microscopy and scanning electron microscopy.The mechanical and wear behavior of carburized and noncarburized alloys were investigated via hardness,tensile,and wear tests.After carburization,the ultimate tensile strength of Alloys 1 and 2 increased to 134.4%and 138.1%,respectively.However,the elongation rate of Alloys 1 and 2 decreased to 62.6%and 64.7%,respectively.The wear depth values of Alloy 2 under noncarburized and carburized conditions and a load of 30 N were 231.2 and 100.1μm,respectively.Oxidative wear changed to abrasive wear when the load transitioned from 15 to 30 N.