Study of High Temperature Oxidation Behavior of Cold Sprayed Novel Ni-20Cr Coating on K21590 Boiler Steel

摘要

The pre-synthesized Ni-20Cr nano-crystalline powder was deposited on K21590 boiler steel by cold-spray process. Nano-crystalline Ni-20Cr powder was synthesized by the investigators using ball milling. The nano-structured coating was developed using cold-spray process with an average coating thickness of 200 u.m and microhardness of 600 HV having porosity < 1.5%. The high-temperature oxidation behavior of bare and coated samples was studied under cyclic conditions at 900 °C for 50 cycles. The kinetics of oxidation was established using weight change measurements for the bare and the coated boiler steel. Various characterization techniques such as X-ray Diffraction (XRD), Scanning Electron Microscopy Energy Dispersive Spectroscopy (SEM/EDS) were used to analyze the oxidation products. The coating was found to offer excellent oxidation resistance and successful in reducing the weight gain of the steel by 71 %.