Wear Resistance of Carbide-Containing Deposited Layers for Drill Pipe Tool Joints

This article considers the prospects for the application of deposition of protective wear-resistant belts of various chemical compositions (hardbanding) on the coupling of a drill pipe lock joint. Studies of drill pipe samples with deposited layers (hardbanding) were carried out: the Vickers hardness (GOST R ISO 6507.1-2007) was determined in the cross section of the deposited layer under a load of 98.07 N (10 kgf), the microstructure was analyzed on sections cut in the cross section of the deposited layer, and wear resistance tests were carried out according to the ASTM G65 method. The composition of carbide phases of such carbide-forming elements as Cr, Nb, Ti, and V was calculated. It was shown that the change in the composition and amount of carbide phase in the deposited layers predictably contributed to the formation of different hardness, which varied in the range from 692 to 774 HV. Comparison of the obtained hardness values and the total weight of the carbide phase showed the absence of a direct relationship between the influence of the composition and amount of the carbide phase on the hardness level. The structure of the alloy matrix makes a large contribution to the hardness values of the deposited metal. It was concluded that, in order to ensure maximum wear resistance of deposited layers operating under abrasive wear conditions, a preference should be given to compositions that form the maximum amount of carbide phases on the basis of chromium.