Effects of alloy elements on the microstructure and crack resistance of Fe-C-Cr weld surfacing layer were investigated. The results show that microstructures of the layer mainly consist of carbides and austenite matri...Effects of alloy elements on the microstructure and crack resistance of Fe-C-Cr weld surfacing layer were investigated. The results show that microstructures of the layer mainly consist of carbides and austenite matrix. Increasing C and Cr contents impair the crack resistance of the layer due to increased amount of brittle carbides. The addition of Ni, Nb or Mo improves the crack resistance of Fe-C-Cr weld surfacing layer by increasing the amount of austenite and forming fine NbC or M 7C 3 carbides in the layer. But, the excessive Nb (>2.50wt%) or Mo (>1.88wt%) impairs the crack resistance of the layer, which has relation with increased carbides or carbide coarsening and austenite matrix solid solution strengthening. The proper combination of C, Cr, Ni, Nb and Mo can further improve not only the crack resistance of Fe-C-Cr weld surfacing layer but also the erosion resistance as a result of fine NbC and M 7C 3 carbides distributing uniformly in austenite matrix. The optimal layer compositions are 3.05wt%C, 20.58wt%Cr, 1.75wt%Ni, 2.00wt%Nb and 1.88wt%Mo.展开更多
文摘Effects of alloy elements on the microstructure and crack resistance of Fe-C-Cr weld surfacing layer were investigated. The results show that microstructures of the layer mainly consist of carbides and austenite matrix. Increasing C and Cr contents impair the crack resistance of the layer due to increased amount of brittle carbides. The addition of Ni, Nb or Mo improves the crack resistance of Fe-C-Cr weld surfacing layer by increasing the amount of austenite and forming fine NbC or M 7C 3 carbides in the layer. But, the excessive Nb (>2.50wt%) or Mo (>1.88wt%) impairs the crack resistance of the layer, which has relation with increased carbides or carbide coarsening and austenite matrix solid solution strengthening. The proper combination of C, Cr, Ni, Nb and Mo can further improve not only the crack resistance of Fe-C-Cr weld surfacing layer but also the erosion resistance as a result of fine NbC and M 7C 3 carbides distributing uniformly in austenite matrix. The optimal layer compositions are 3.05wt%C, 20.58wt%Cr, 1.75wt%Ni, 2.00wt%Nb and 1.88wt%Mo.
