Anti-corrosion aluminised coating - for ferrous metals with brazed joints
Номер патента: DE2452446A1
Опубликовано: 13-05-1976
Автор(ы): Hossein Borougerdi, John A Puchot, Michael F Dean
Принадлежит: Chromalloy American Corp
Опубликовано: 13-05-1976
Автор(ы): Hossein Borougerdi, John A Puchot, Michael F Dean
Принадлежит: Chromalloy American Corp
Реферат: Prodn. of a thermally diffused corrosion protecting aluminised layer on stainless steel components with brazed joints where the braze material is a non-ferrous alloy at m.pt. 607-1052 degrees C and esp. an alloy based on Cu, Ag, or Au, with m.pt. 635-1010 degrees C, involves protecting the braze from excessive Al penetration by selectively plating it with a 0.005 mm layer of Ni. Selective plating is achieved by chemically depositing Hg on the braze, immersing in aq. HNO3 or CrO3 to remove Hg and passivate the steel, followed by electroless Ni plating which deposits only on the braze. After aluminizing, corrosion protection is further improved with one or more silicate coatings opt. followed by chromate/phosphate treatment. Used for mfg. components, e.g. for turbines, which draw in air and operate in marine conditions. Weakening of brazed joints by excessive penetration of Al is prevented.
Corrosion resistant coating system for ferrous metal articles having brazed joints
Номер патента: US3898052A. Автор: Michael F Dean,Hossein Borougerdi,John A Puchot. Владелец: Chromalloy American Corp. Дата публикации: 1975-08-05.