Developing Layers of Highly Corrosion- and Wear-Resistant Fe-Based Ultrafine-Grained Laser Cladding on 27SiMn Steel
摘要
In order to obtain the Fe-based cladding layer with excellent performance, using 27SiMn steel as the base material and adopting the synchronous powder feeding method, through in situ self-generated carbides and adjusting the dosage of niobium element, the related changes of the microstructure, hardness and corrosion resistance of the cladding layer were studied, and the optimal performance of the Fe-based laser cladding layer was obtained. The results show that within the range of 0-1.2 wt.%, the change of Nb content has no effect on the forming quality of the cladding layer and the phase composition of the cladding layer. An appropriate amount of Nb element has the effect of refining the grains. The grain size, hardness and corrosion resistance of the Fe-based cladding layer all show a trend of increasing first and then decreasing. When the addition amount of Nb is 0.9 wt.%, the grain size of the cladding layer reaches the sub-micron ultrafine crystal scale of 0.96 μm, the average microhardness of the cladding layer reaches 960 HV0.2, and the cladding layer shows the best corrosion resistance. The anti-friction and wear performance of this cladding layer is 13.6 times that of the 27SiMn substrate. The anti-corrosion and anti-wear performance is 7.3 times that of the 27SiMn substrate.