Wear-Resistant Cr₃C₂–15% Ni and Cr₃C₂–28% Ni Hard Alloys and Production and Industrial Testing of Valves for Oil Well Pumps from These Materials

Abstract

The corrosion resistance of Cr₃C₂–15% Ni alloy in solutions of acids, alkalis, and salts is studied. It is found that the corrosion rate of this alloy is one fifth to one thirtieth that of 40Cr13 stainless steel, stellite, and WC–8% Co alloy used to manufacture valve pairs for oil well pumps. The features in production of balls from sintered workpieces of the Cr₃C₂–15% Ni alloy and of valve seats from the Cr₃C₂–28% Ni alloy have been determined. The modes of rough machining, finishing, and abrasive mechanical treatment of chromium carbide hard alloys have been optimized depending on duration of the processes and particle size of the B₄C powder. The batches of valve pairs manufactured from chromium carbide alloys were tested in industrial conditions at JSC “Ukrnafta”. The lifetime of the valve assembly made of the corrosion-resistant had alloys is more than two years, which is three to five times higher than the efficiency of such parts from conventional materials. Data are provided on the developed standards for “seat–ball” valve pairs made of chromium carbide alloys (TU U. 28.4–02126745–001–2002).