Effects of TiC Particles on Microstructure and Abrasion Resistance of Fe-C-Cr-Si Alloy Hardfacing Layers

Fe-C-Cr-Si hardfacing alloy layers were deposited by the method of submerged arc welding. The effects of TiC particles on the microstructure and abrasion resistance of the hardfacing alloy layers were researched by microstructure observation, hardness measurement and abrasion wear testing. The results show that the matrix of hardfacing alloy layers were all α-Fe; when TiC content increased, primary M7C3 grains gradually reduced in size from 40-80 μm to 15-25 μm and distributed more dispersively with their amount increasing, and the reinforce phases such as TiC2 and TiC were observed. Dispersively and close distributed M7C3 particles were favorable for uniformly wearing on the hardfacing alloy layer surface, refrained from premature failure because of priority wearing of the brittle eutectic with larger size and improved its abrasion resistance. The abrasion resistance of the hardfacing alloy layers first increased, then decreased and increased again with the increase of TiC content, and the dominating wear mechanism changed from micro-cracking to micro-cutting.