Research Of Carbonitride Alloying Open Arc Hardfacing Flux-cored Wire And Its Hardfacing Metal

The carbonitride alloying open arc hardfacing flux-cored wire had been developed.The influence of microalloy element and the temper temperature for microstructures and nature of hardfacing metal had been discussed.This new type carbonitride alloying open arc hardfacing flux-cored wire has better welding processing property and welding metallurgy property,and the mechanical property of the hardfacing metal can meet the operating requirements.The microalloy element Nb,Ti,V had been added to the flux to refine the crystal grain of hardfacing metal and reduce the nitrogen ionic and porosity in hardfacing metal.The reaction product of Nb,Ti,V and carbon,nitrogen are minimal carbides,nitrides and carbonitride, which dispersed distributing in hardfacing metal have deposited strengthening action.In all Nb,Ti,V are added to increase the mechanical property of hardfacing metal.The hardness values of hardfacing metal are from 36.5 to 45.5HRC,the microstructures of hardfacing metal consist of lath- shaped martensite and carbonitride of Cr,Ti,V and Nb. These carbonitride are hard to be discomposed and have better stability and high temperature temper-resistant property.The hardness can reach the highest when the temper temperature is 550℃and it is almost hold the line when the temperature is higher than 550℃.The weight loss of wear of carbonitride alloying self-shielded hardfacing flux-cored wire is plastic grinding crack cut by abrasive particle and block desquamation at the place of carbonitride,and the hardfacing metal has better wear-resisting property at the tempering range of 480~520℃.The microstructures,hardness,wear-resisting property and the shape and precipitating behavior of second-phase particles of the carbonitride alloying open arc hardfacing flux-cored wire,submerged arc flux-cored wire and British open arc flux-cored wire had been compared.The result showed that the hardfacing metal of the carbonitride alloying open arc hardfacing flux-cored wire have steady mechanical property and high temperature temper-resistant property.