Abstract:

Four types of surfacing welding electrodes ware homemade and foundry tungsten carbide welding seam is quenched or deep cooling treated according to fragmentation, abrasion and desquamation failure form of sinteredcarbide welding layer of milling shoe. N and K model electrodes used in test is flaked likely. Thin canal cast tungsten carbide welding rod possesses the best impact abrasion resistance. The weight ratio of tungsten carbide and thin tube affects directly on peening wear resistance and peeling of tungsten carbide. The reciprocity of shadow effect of hard phase of welding seam and fasten effect of basal body and bonding phase to hard phase is the reason of strengthening impact abrasion resistance if the weight ratio of tungsten carbide and thin tube is suitable. The impact abrasion resistance of cast tungsten carbide welding layer of milling shoe increases 17.4% by quenching. It also increases 43% by cryogenic treatment after quenching. Structure analysis shows that hard phase of welding layer has little been affected by cryogenic treatment. The Structure is also η+ M6C + M23C6+ M7C3。the change of component , shape and distribution of bond phase is the main reason of enhancing impact abrasion resistance.

Key words: cast WC/Ni or Fe based alloy composite, tungsten carbide, impact abrasion resistance, Cryogenic treatment, mill shoe, hard facing layer