High temperature particle jet erosion of nickel- and cobalt-based alloys
Higher operating temperatures can increase the effectiveness of different technical processes, e.g. turbines, combustion furnaces and cyclone separators. The combination of the increasedtemperatures with the stresses and strains necessitate new hardwearing materials. Theresearch of the influence of high temperatures and oxidation on the wear resistance hasmainly been conducted on single-phase materials. In the current research, the influences of temperature, impact angle and kinetic energy of theparticles are examined. Therefore, high temperature particle jet erosion tests of a nickel-basedand a cobalt-based alloy were conducted. Hastealloy® C22 and Ultimet® Alloy were chosen,due to the high resistances against both corrosion and abrasion. The specimens are PTA-welded layers on steel plates, partially reinforced with different carbides, including fusedtungsten carbides and titanium carbides. Initially, only carbides of the same grain size wereused. Further tests were conducted on alloys with a mixture of carbides, varying in type andsize. These tests were conducted in a specially designed testing machine with a variety ofparameters. This includes temperatures of 750 °C, different particle velocities and impactangles. Oxidation tests were used to isolate the influence of the corrosion on the wearresistance at high temperatures. The results of this research provide a better understanding of the properties and capabilities ofthe alloys and carbides.