The paper discusses the successful use of modern automatic overlay technology to apply weld overlay for surface protection against corrosion or erosion/corrosion for waste-to-energy boilers, utility coal-fired boilers and kraft recovery boilers. The current corrosion problems and the modes of corrosion involved in these boilers are discussed. Also discussed are successful applications and performance of various corrosion-resistant overlays for corrosion protection and life extension of boiler tubes in the aforementioned boilers.