Study On Plasma Torch And Wear-Resistant Alloys By Pta Powder Surfacing

Aiming at the problem of wear failure, the research about surface strengthened of common materials by PTA powder surfacing was carried out in this paper .On the basis of referring to the data at home and abroad, a new type of plasma torch was created which has two jets. The inner jet has a tiny hole which diameter is 5mm.There are two parts at end of the jet which are joined through thread. Reasonable passageway was designed in the plasma torch which provided good cool condition for all parts. The torch whose structure is suitable is convenient to use in the process of PTA powder surfacing. A new type of alloy powder which had good wear-resistant performance had been made and studied in this paper. The powder consisted of Cr, Mn,W on the basis of nickel base alloy. Orthogonal experiment of PTA powder surfacing was performed by orthogonal design ,with factors: element of Cr, Mn,W and index: HRC hardness of Q235 steel surface by the orthogonal polynomial regression. The optimum parameters of alloy powder recipe are as following: Cr=10%, Mn=4%, W=7%.The result of wear-resistant experiments on the nine different components of surfacing layer showed that wearability of layer increases with an increase of hardness. There are a lot of white hard phases which exist as the wear-resistant frame. This paper has important meanings on theory and engineering benefits which provides a solution of how to strengthen the surface of mechanical parts, increase their wearability and working life.