Erosion behavior of Pulverized Coal Burner Nozzle material hardfaced by solid wire and flux cored wire electrode

摘要

In present study, an attempt was made to reduce the erosion rate of the Pulverized coal burner nozzle material. For better resistant to erosion, material was hardfaced by Gas Metal Arc Welding (GMAW) by using solid wire electrode and flux cored wire electrode under same welding conditions. The substrate steel hardfaced with flux cored wire electrode resulted in high microhardness as compare to solid wire electrode. The erosion study was conducted, using an air jet erosion test rig at a particle velocity of 50 m/s. Ductile erosion behavior is observed in the case when the substrate steels is hardfaced with solid wire whereas brittle erosion behavior is observed when the substrate steels is hardfaced with flux cored wire. At a low angle of impingement, the abrasive type cutting is the dominating factor for material removal, and at a higher angle of impingement, impact-type as well as abrasive-type cutting actions play critical roles. Plastic deformation characterized by pitting and cutting action was also observed. Scanning electron microscopy (SEM) technique was used to analyze the eroded surface. It was concluded that damaged surfaces of Pulverized coal burner nozzle material can be successfully hardfaced and improvement in erosion resistance was observed.