Influence of Ni addition on erosive wear characteristics of multi-component white cast iron at elevated temperature

Abstract

Comparing to the carbide-forming elements such as chromium (Cr), molybdenum (Mo) and tungsten (W), nickel (Ni) has a feature of preferentially dissolved into the matrix instead of forming carbides. The carbide-forming elements which were suppressed to dissolve into the matrix would then be encouraged to form more carbides. Hence, the improvement of erosive wear performance of the materials can be expected.In this study, approximately 0, 3, 5 mass % of Ni was added into the Niobium (Nb)-containing multi-component white cast iron and the influence of Ni on the erosive wear characteristics was investigated at elevated temperature (1173K). Alumina balls which hardness is 1140 HV (average diameter: Ø1.16 mm) were used as impact particles at velocity of 30m/s. As results, the oxidation amount was suppressed at the same level, and the amount of eutectic carbides was increased with the addition of Ni as expected. The high temperature hardness was increased with Ni addition due to the high hardness carbides, resulting in the improvement of the erosive wear property and material 5Nb-5Ni exhibited the most excellent erosive wear characteristics at 1173K. Therefore, by promoting the formation of carbides and remaining the heat resistant property, the addition of Ni is an effective method to improve the erosive wear characteristics of Nb-containing multi-component white cast irons at 1173K.