Microstructure and properties of Fe-Cr-C-B-W alloy by self-shielded flux-cored wire open-arc surfacing

Five Fe-Cr-C-B-W alloy samples with different W contents were prepared by self-shielded flux cored wire arc surfacing technology. Microstructure and properties of surfacing alloys were analyzed by metallographic microscope, scanning electron microscope, X-ray diffractometer, Rockwell hardness tester and wear tester. The results show that the microstructure of the surfacing alloy consists of martensite, retained austenite, M₇(C,B)₃, M₃(C,B), Fe₃W₃C and WC. Most of W is migrated to the grain boundary to produce Fe₃W₃C C deficiency composite phase which is more stable than the WC. There are no typical primary WC hard phase particles in the surfacing layer. With the increase of W content, the eutectic hard phase M₇(C,B)₃, M₃(C,B) and Fe₃W₃C increase, and the spacing decreases. And they are continuous and evenly distributed. When the addition amount of W is 12%, the wear resistance of the surfacing layer is the best.