Two-stage conversion treatment

Details Two-stage conversion treatment Two-stage conversion treatment

C - Chemistry, Metallurgy

23

C

C23C 22/83 (2006.01) B05D 5/00 (2006.01) B05D 7/00 (2006.01) C23C 22/34 (2006.01) C23C 22/44 (2006.01) C23C 22/73 (2006.01)

Patent

CA 2548975

The invention relates to a method for the two-stage corrosion prevention treatment of metallic surfaces. According to the inventive method, (a) in a first step, the metallic surface is brought into contact with a chromium-free first aqueous solution having a pH value of between 1.5 and 5, and containing a total of at least 0.01 g/l and up to 10 g/l Ti and/or Si ions, and at least a quantity of fluoride such that the atomic ratio Ti to F and/or Zr to F and/or Si to F is between 1: 1 and 1: 6, and then (b) in a second step, the metallic surface is brought into contact with a chromium-free second aqueous solution having a pH value between 1.5 and 5, containing a total of at least 0.01 g/l and up to 10 g/l Ti and/or Zr and/or Si ions, and at least a quantity of fluoride such that the atom ratio Ti to F and/or Zr to F and/or Si to F is between 1: 1 and 1: 6, and additionally containing such a quantity of soluble anions of oxoacids of molybdenum and/or wolfram in the oxidation stage VI, that the entire concentration of molybdenum and/or wolfram, calculated as MoO42- and/or WO42-, is between 5 and 1500 mg/l.

L'invention concerne un procédé de traitement en deux étapes anticorrosion de surfaces métalliques. Selon ledit procédé: (a) dans une première étape, la surface métallique est mise en contact avec une première solution aqueuse exempte de chrome, dont le pH est compris entre 1,5 et 5 et qui contient un total d'au moins 0,01 g/l et jusqu'à 10 g/l d'ions Ti et/ou Si, ainsi qu'au moins une quantité de fluorure telle que le rapport atomique Ti à F et/ou Zr à F et/ou Si à F est compris entre 1:1 et 1:6; ensuite (b) dans une seconde étape, la surface métallique est mise en contact avec une seconde solution aqueuse exempte de chrome dont le pH est compris entre 1,5 et 5, et qui contient un total d'au moins 0,01 g/l et jusqu'à 10 g/l d'ions Ti et/ou Zr et/ou Si, au moins une quantité de fluorure telle que le rapport atomique Ti à F et/ou Zr à F et/ou Si à F est compris entre 1:1 et 1:6 et, en outre, une quantité d'anions solubles d'oxacides de molybdène et/ou de tungstène, dans l'étape d'oxydation VI, telle que la concentration totale de molybdène et/ou de tungstène, calculée en tant que MoO¿4??2- ¿et/ou WO¿4??2-¿, est comprise entre 5 et 1500 mg/I.

Affiliated with

Also associated with

Rating

Two-stage conversion treatment does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Two-stage conversion treatment, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Two-stage conversion treatment will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFCA-PAI-O-2065920