This paper shows how controlled additions of copper (Cu) and tungsten (W) improve the pitting corrosion resistance of super duplex stainless steel.
Extended immersion in NaCl solution produced a thicker passive layer on the alloy with the higher copper content (Ferralium® 255 meets the general specification of S32550/2507Cu). Further electrochemical studies confirm the benefit of higher copper additions in resisting crevice corrosion in more aggressive solutions.
