非鉄材料

摘要

This report reviews recent progress in the research and development of corrosion protection technologies for nonferrous materials such as titanium, nickel, copper, and aluminum. Crevice corrosion resistant titanium alloys AKOT, TICOREX and SMI-ACE were newly developed which provide competitive low cost and almost the same corrosion resistance as Ti-0.15Pd. Hastelloy C-22, Hastelloy G-30, Inconel 690, and MAT21 were also developed which possess much more excellent corrosion resistance compared to the existing nickel alloys. Copper tubes in hot water supply system encountered pitting corrosion and copper alloy condenser and heat exchanger tubes in sea water erosion-corrosion, etc. and their countermeasures are described. Painted aluminum alloy sheets for automobiles suffered from filiform corrosion, and it could be prevented through alloy design, zinc-phosphate treatment, and/or zinc plating. In automotive heat exchangers such as radiator, heater, condenser, evaporator, etc. made from aluminum alloys, de-icing salt splash, engine coolant water, and/or condensate solution have been their severe corrosives, and their countermeasures are explained.