Microstructures and properties of friction surfaced coatings in AISI 440C martensitic stainless steel

While martensitic stainless steel AISI 440C is an attractive material for wear protection in many industrial applications, it is difficult to realize satisfactory coatings in this material using conventional weld overlay processes. Friction surfacing, a promising solid-state process, can help in this regard. In the current study, alloy 440C coatings were successfully made on low carbon steel substrates using friction surfacing. Bend and shear tests on coated specimens indicated excellent coating/substrate bonding. Microstructures, corrosion behavior, and wear performance of these coatings were compared with standard heat treated alloy 440C bulk material. While friction surfaced coatings in alloy 440C exhibited superior corrosion resistance to standard heat treated alloy 440C bulk material, their wear resistance was found to be somewhat inferior. Apart from these studies, experiments were conducted to assess the potential of the process for wide area coverage. Studies show that it is possible to achieve well-bonded coatings consisting of multiple overlapping tracks with excellent inter-track bonding. Overall, the current study demonstrates that friction surfacing is a very useful process for producing wear resistant coatings in difficult-to-fusion-deposit materials such as alloy 440C martensitic stainless steel. (c) 2012 Elsevier B.V. All rights reserved.