METHOD OF PLATING BY MEANS OF SUBMERSION INTO MOLTEN ELECTROLYTE OF STRIP MADE OF HIGH-STRENGTH STEEL Russian patent published in 2009 - IPC C23C2/02 

FIELD: metallurgy.

SUBSTANCE: invention relates to plating made of zinc and/or aluminium by means of submersion into molten electrolyte of strip made of high-strength steel with different alloying ingredients, particularly, Mn, Al, Si and/or Cr. Method including following stages: a) strip in deoxidising atmosphere with content H₂ at least from 2% up to 8%, it is heated up to temperature from 650°C up to 750°C, at which alloying species are not diffuse yet and only in small quantity diffuse on surface, b) surface consisting of mainly from pure iron by means of strip's thermal treatment of duration from 1 up to 10 sec at temperature from 650°C up to 750°C in built in to pusher-type furnace reaction chamber with oxidising atmosphere with content O₂ from 0.01% up to 1%, transform into layer of ferric oxide, c) then strip in deoxidising atmosphere with content H₂ from 2% up to 8% by means of following heating up to temperature maximum 900°C annealed, and then it is cooled up to temperature of molten electrolyte, herewith layer of ferric oxide at least on its surface, restored into pure iron.

EFFECT: receiving of strip with improved surface.

9 cl, 1 dwg