Wear behaviour of Cr3C2–Ni cermet reinforced hardfacings

Abstract

Submerged arc welding (SAW), plasma transferred arc welding (PTAW), and tungsten inert gas welding (TIG) technologies were used to produce austenitic stainless steel (SS) and nickel alloy (Ni) matrix based hardfacings without reinforcement and reinforced by Cr3C2–Ni cermet. As a substrate material normalized structural steel S355 has been chosen. Mechanical properties of produced hardfacings were assessed in terms of hardness (HV/30) and wear resistance tests. The latter property was analysed under different wear conditions: two-body (ASTM G132) and three-body (ASTM G65) abrasive wear tests. Microstructure and phase evolution were analysed by scanning electron microscopy (SEM) and X-ray diffraction analysis (XRD), respectively. Cermet particles in all the conducted tests proved its’ selection – hardness and wear resistance of the reinforced hardfacings substantially increased. The addition of Cr3C2–Ni cermet increased the hardness twice on average in all utilized technologies leading to the higher wear resistance in further tests. Tendency of wear rate reduction is less expressed in SAW hardfacings, but in PTAW and TIG cases the strengthening effect is obvious: 8.6 and 8.1 times higher wear resistance of SS and Ni based PTAW hardfacings, respectively, and 7.5 and 4.8 times higher for TIG hardfacings. XRD analysis supported wear tests results proving the formation of the complex compounds.