Effect of titanium and tungsten on the structure and properties of heat-abrasion resistant steel

The effect of Ti and W on the microstructure and properties of austenitic heat-abrasion resistant steel was studied using microstructure examinations, hardness tests, wear resistance and oxidation resistance experiments. The results indicated that the specimens containing Ti and W had a notable increase in hardness and wear resistance, but a slight decrease in oxidation resistance. The structures of specimens with Ti and W included some MC carbides, dispersedly distributed inside grains and at grain boundaries; these specimens also showed an increase in material properties. From oxidation kinetics analysis, the oxidation of austenitic heat-abrasion resistant steel specimens generally agree with parabola rule, oxidation activation energies kp1 and kp2 are calculated to be 304 and 128 kJ/mol. The oxide films composed of Cr2O3, spinelle (FeCr2O4, NiCr2O4), and some Fe3O4 were continuous and compact. Cr2O3 plays the vital role in the oxidation resistance based on the oxidation activation energy calculation.