Laser Surface Remelting for Performance Improvement of Shafts Repaired by Cold Spray Additive Manufacturing

Cold spray additive manufacturing (CSAM) is an important contributor to the circular economy as it enables the refurbishment and reuse of crucial industrial components - reducing raw materials and energy consumption. Polycontrols has previously shown that large defects in steel shafts can be effectively restored to dimensional specifications by CSAM. The deposition of a millimetre-thick stainless-steel coating by CSAM ameliorated the bare steel corrosion resistance; however, the electrochemical behavior of the as-sprayed surface still lacked the desirable properties. In this work we present the effects of laser surface remelting under specific parameters on the microstructure and corrosion resistance of cold sprayed stainless steel 316L deposits, evaluated by cyclic polarization in 0.6M NaCl solution. It is shown that laser-treated deposits can behave like a bulk stainless steel, i.e. they display a clear passivation plateau and comparatively low corrosion currents.