Welding processes for wear resistant overlays

This paper presents a comprehensive survey of welding processes used to deposit wear resistant overlays. It is based on both literature review and research work performed at the Canadian Centre for Welding and Joining. The focus is on the two most popular material systems used for wear resistant overlays: nickel-base with the addition of tungsten carbide particles, and iron-base in which chromium carbides of the form M7C3 nucleate during solidification. The processes surveyed in detail are plasma transfer arc welding, submerged arc welding, laser beam welding, gas metal arc welding-related processes using tubular wires, oxy-acetylene flame brazing, and the still-experimental applications of friction stir processing. Cost and market are key factors influencing technical decisions on wear protection overlays, but the information is scarce and often tightly guarded. An informal survey from our industrial partners is included.