The Need

Hard-facing alloys are used for a variety of applications due to their material properties, which include high galling resistance, good wear resistance, high strength and erosion performance, corrosion performance, and high hardness. Most hard-facing alloys fall into one of three alloy categories: iron-based, nickel-based, and industry standard cobalt-based alloys. Several iron-based, cobalt-free, “modified-stainless steels” are currently used by the nuclear industry primarily for valve seat applications. These alloys have had limited success for various reasons, such as solidification cracking during welding, poor weldability, cracking in service, poor wear properties at service temperatures, and poor acceptance by industry in general. There is an unmet need for alternative cobalt-free hard-facing alloy.

The Technology

Researchers at The Ohio State University, University of Tennessee, and Oak Ridge National Laboratory, led by Dr. Sudarsanam Babu, have developed a new alloy that that will provide high galling, wear, and erosion resistance. The new alloy has been manufactured in powder-form and may be applied via powder processing to a component and bonded using conventional powder metallurgy processes.

Commercial Applications

• Automotive Technology
• Aero-Engines and Gas Turbines
• Nuclear
• Oil and Gas Machine Tooling

Benefits/Advantages

• The alloy provides excellent galling and sliding wear properties at room temperature and through 343°C nuclear plant operating temperatures.
• The alloy rivals galling and slide-wear performance of cobalt-based alloys like STELLITE 6 and 21 across the range to 343°C.
• Lowered stacking fault energy, high volume fraction of hard secondary phases like carbides and nitrides minimize detrimental phases of the alloy.