It is well understood that many environmentally induced cracking requires the confluence of susceptable material stress and corrosive media. Weld overlay and conformal plate cladding technologies have been employed to mitigate these mechanisms by surface alloy enhancement. Although these procedures are succesful relatively slow production rates in terms of surface protection and the difficulties associated with post weld heat treatment (PHWT) requirements within the constraints of short turnarounds are problematic. The employment of metallurgically cold High Velocity thermal spray metal cladding technology with specifically engineered alloys for the process has been tested and employed for large scale protection of both carbon steel and 316SS vessels. This approach has been effective in mitigation of Hydrogen blistering Stress Corrosion Cracking and Sulphide Stress Cracking. The mechanisms with respect toeffective substrate isolation as well as the mitigation ofcorrosion related hydrogen generation arediscussedwithlarge scale in-situ case studies cited where this technology provided effective cracking prevention and mitigatedneed for field PWHT requirements.