The Heat Treatment Process Of Forging State Iron-based Alloy Microstructure And Properties Of The Impact Its Wear Resistance

FeCr2.2C1.92M and FeCrg.5C2.37M alloying iron were prepared by using a forging process, and their corresponding modified samples were cast. Then, their heat-treatment processes were explored from the best forged samples. By means of macroscopic hardness test, impact test and fracture scan, the best mechanical properties of them were investigated. The microstructure and micro-mechanism of them going through forged samples were observed and researched by using OM,3D Digital Microscope, SEM and TEM. The wear-resistance and track of them have been investigated with Micro-fricative Wear Tester. And the results showed that:(1)With their hot deformation increased, the hardness of FeCr2.2C1.92M and FeCr8.5C2.37M were decreased and their impact toughness increased on the forged conditions of 980℃and 1050℃.Ultimately, the optimum deformation of FeCr2.2C1.92M and FeCr8.5C2.37M should respective be 50% and 40%.(2) After hot-deformation, the best heat-treatment processes of FeCr2.2C1.92M and FeCr8.5C2.37M were developed.FeCr2.2C1.92M: 960℃6h annealing+880℃1h quenching+350℃1h tempering and the mechanical properties are hardness (HRC57.3)and impact toughness (26.3J·cm-2). FeCr8.5C2.37M:1000℃6h annealing+840℃1h quenching+450℃lh tempering and the mechanical properties are hardness (HRC55.8) and impact toughness (20.3J·cm-2).(3)During annealing, the nucleation and growth of FeCr8.5C2.37M's pearl shapes are:a leader in cementite phase and the formation of ferrite phase, are working together as pearlite nuclei.And then the nuclei grew up in the pearlite grain group.After quenching+tempering, FeCr2.2C1.92M and FeCr8.5C2.37M samples were mainly twin martensite, which had been the various types of martensite. FeCr2.2C1.92M:butterfly-shaped martensite,{259}γ-type martensite and{225}γ-type martensite.FeCr8.5C2.37M:a thin sheet martensite, {259}γ-type martensite,{225}γ-type martensite and{3 15 10}γ-type matrensite. (4) By using dual chrome steel ball,the forging state and heat-treatment state of FeCr2.2C1.92M and FeCr8.5C2.37M were respectively carried out through reciprocating flat sliding wear test.For FeCr2.2C1.92M alloy, the wear volume loss of the forging state sample was more than the best heat-treatment state, and therefore the best heat-treatment state sample has the better wear performance. For the forging state of FeCr8.5C2.37M alloy, at the load of 20N, the wear volume loss of the forging state sample was more than the best heat-treatment state,and therefore the best heat-treatment state sample has the better wear performance.But in the load from 40N to 120N, the wear volume loss of the forging state sample was less than the best heat-treatment state, and therefore the forging state sample has the better wear performance.