Erosion behaviour of HVOF sprayed (CR3C2-35%NICR) +5%Si coatings

Abstract

In the present study, (Cr3C2-35%NiCr) +5%Si cermet coatings were deposited on a Fe based T22 steel substrate to reduce the damage caused by erosion boiler applications. Erosion studies were conducted on uncoated as well as HVOF coated steels. The erosion experiments were carried out using an air-jet erosion test rig according to ASTM G-76 standard at a velocity of 30 m/s and at different impingement angles of 30 , 60 and 90 . Silica sand particles of size ranging between 150 to180 ?m were used as erodent. Analysis of weight-loss data and volumetric steady state erosion rates for different coatings and substrate alloys are evaluated. The bare T22 steel followed ductile erosion mode where as (Cr3C2-35%NiCr) +5%Si coating exhibited mixed behaviour respectively.