Weldability of Cr₃C₂/Ni₃Al hardfacing material

Cr₃C₂/Ni₃Al composite is a potential candidate for elevated temperature surface hardfacing material.The weldability is very important for its application.When the Cr₃C₂-NiAl-Ni welding wires produced by pressureless sintering process in vacuum were welded on the surface of carbon steel and heat resistant steel by the manual gas tungsten arc welding,crack-free Cr₃C₂/Ni₃Al composite coatings were obtained.The Cr₃C₂/Ni₃Al composite possesses good weldability and is suitable for industry application as hardfacing material of iron base material.The good weldability is attributed to following factors:(1) Cr₃C₂ is dissolved during hardfacing.C precedes Al to be oxidized in melting pool thereby protects Al from oxidation severely.(2) Some Fe diffuses into hardfacing metal from steel and Cr that comes from dissolved Cr₃C₂ enters into Ni₃Al matrix,which improves the weldability of Ni₃Al markedly.