Passive films formation on thermally processed industrial titanium alloys,in concentrated chloride solutions

In this paper, the passivation behaviour of the thermal treated titanium al loy Ti-1Ni-0.5Mo in concentrated chloride solutions, at high temperatures i s presented. The alloying of the titanium with molybdenum and nickel has th e following effects on the passivity behaviour of the industrial, ternary T i-1Ni-0.5Mo alloy: the shifting in noble direction of the allow corrosion p otentials due to the couple galvanic effect of the molybdenum and nickel: t he enlargement of the alloy passive potential ranges as result of the molyb denum and nickel participation with its insoluble compounds at the Consolid ation of the alloy passive film; the decrease of the alloy passive current densities because of the same consolidation effect of the passive layer; bo th the titanium and Ti-1Ni-0.5Mo alloy do not present pitting corrosion; th e decrease of the alloy corrosion rates in concentrated chloride solutions, in comparison with the base metal, The thermal treatment by forging improv ed the protective properties of the passive films formed on the alloy surfa ce.