Investigation of surfacing electrode with high hardness based on lath martensite

Based on lath martensite and carbides, the surfacing electrode with high hardness was developed owing to adding graphite, ferrotitanium (Fe–Ti), ferrovanadium (Fe–V), etc., in electrode coating. Although the content of carbon element in deposited metal is very high, the lath martensite is generated in welded metal because TiC–VC particles formed by means of high temperature arc metallurgic reaction. The mechanism of crack resistance and wearability were systemically studied by cracking test and wear test. The results show that the hardness of surfacing metal is above 60 HRC. Surfacing layers have fine crack resistence and high wearability. The mass loss of surfacing metal in unit area is only one-eighth comparing to EDZCr-C-15 electrode. It also greatly excels EDZCr-C-15 in crack resistence. Carbide particles formed by arc metallurgic reaction are dispersedly distributed in matrix structure. In the course of wear, carbides embedded in lath martensite provide a composite effect of hardness and toughness.