Improved Hardfacing for Drill Bits and Drilling Tools

New flame spray hardfacing, DSH (DuraShell Steel Hardfacing, US patent pending), is developed to improve thermal conductivity, abrasion wear and erosion resistance for subterranean drilling application. The hardfacing materials consist of spherical cast WC/W2C and Ni-Si-B alloy powders. The hardfacing compositions are tailored for flame spray and laser cladding processes. Typically, the hardfacing comprises hard spherical cast WC/W2C particles uniformly distributed in a tough Ni-alloy matrix. The hardness of WC/W₂C exceeds 2100 Hv_.3 and Ni alloy matrix varies from about 400 to 700 Hv_.3. High stress and low stress abrasion resistances of these hardfacings were characterized and compared to the conventional cast WC/W₂C and Ni-Cr-Si-B-Fe hard coating. The increase in thermal, wear, and erosion resistances of DSH hardfacing improve the durability of PDC steel body bits and drilling tools and their cost effective performance. Several case studies of DSH hardfacings on drill bits are described.