Wear Resistance of FeCrAlNbNi Alloyed Zone via Laser Surface Alloying on 304 Stainless Steel

Abstract

In order to enhance the wear resistance of 304 stainless steel, a FeCrAlNbNi alloyed zone (AZ) was deposited on its surface using laser surface alloying technology, and the wear resistance of the AZ was investigated. The results found that the AZ had a dense and fine structure and no obvious defects, and the microstructure was mainly composed of equiaxed dendrites. A large amount of iron compounds and iron-based solid solutions in the AZ made the average microhardness of the AZ about 2.6 times higher than of the substrate. The friction and wear performance of the AZ at 25 °C, 200 °C, 400 °C and 600 °C better than that of the substrate. As far as the AZ was concerned, the abrasion resistance was the best under normal temperature environment. At 200 °C and 400 °C, due to the repeated extrusion and grinding of the friction pair, the oxide layer formed on the AZ surface was prone to microcracks and peeling off, which reduces the wear resistance. Especially at 400 °C, the formation and peeling speed of the oxide layer is accelerated, and the wear resistance is the lowest. However, when the temperature reached 600 °C, an Al2O3 layer was formed. And the Al2O3 has greater wear resistance to protect the AZ. At this time, the wear resistance was greatly improved compared to 200 °C and 400 °C. Therefore, as the temperature increased, the wear resistance of the AZ first decreased and then increased.