Abstract: Method of zinc phosphatization of substrates essentially based on iron, zinc or their alloys, comprising successively:(1) one or several alkaline degreasing steps,(2) one or several rinsing steps with running city water,(3) an activating and refining step,(4) the zinc phosphatization step proper,(5) one or several rinsing steps with water,(6) preferably, a passivating final rinsing step, particularly by means of salts of hexavalent chromium or mixtures of hexavalent chromium and trivalent chromiumcharacterized by the fact that, to carry out the activating and refining step, recourse is had to a bath comprising, besides the conventional constituents among which are particularly at least one Jernstedt salt in a proportion corresponding to about 1 to 100 ppm of titanium, a proportion of 10 to 700 ppm, preferably from 50 to 200 ppm, of at least one alkane-phosphonic acid of formula ##STR1## or at least one of the alkali or ammonium salts corresponding to the abovesaid alkane-phosphonic acids, the pH of the bath b

Abstract: Process for the treatment by chemical conversion, within very short spaces of time of substrates of zinc or of one of its alloys especially of continuously zinc coated steel coils, wherein the bath employed in the phosphatization step proper comprises, besides the conventional constituents, a proportion of 0.3 to 2 g/l of Fe.sup.2+ ions, this bath comprising also from 0.2 to 1.5 g/l, preferably from 0.2 to 1.2 gl/ of Zn.sup.2+ ions and from 0.3 to 2 g/l, preferably from 0.3 to 1.2 g/l of Ni.sup.2+ ions, the weight ratiosZn/Ni and Zn Febeing comprised between 0.1 and 5, these ratios being preferably comprised respectively between 0.4 and 2 and between 0.25 and 4.

Abstract: Chemical conversion bath with zinc characterized by the fact that it comprises, besides the conventional constituents, an effective amount of fluorophosphate ion of the formula:F--PO.sub.3.sup.2-which can be introduced in the form of the corresponding acid, one of its alkali, alkaline-earth or ammonium salts or its zinc salt.

Abstract: The invention relates to a composition and a process for the treatment, more precisely the "post-treatment" of phosphatized metal surfaces, particularly when the surfaces must be subsequently covered with a coat of paint. It relates also to a process for the preparation of the composition and a concentrate useful for this preparation. The composition comprises an effective proportion of trivalent titanium compound and it is presented with an acid pH, the proportion of said compound being sufficient for the corresponding composition to confer on the treated metal surface a protection equivalent to that obtained with known chromatizing solutions. More particularly, the composition contains trivalent titanium at a concentration of 0.01 to 2 g/l, preferably from 0.2 to 0.6 g/l and has a pH of 2 to 7. Reducing means can be arranged to regenerate the trivalent titanium in the treatment solution continuously.

Abstract: The invention relates to a process of phosphating surfaces of iron and of steel with manganese.The abovesaid process is characterized by the fact on the one hand, that it does not include a refining treatment preceding the proper phosphating, and on the other hand, that the alkali degreasing bath has a pH of 9 to 12 and includes in suspension bivalent manganese in orthophosphate form.

Abstract: A treatment of iron or steel surfaces to give them enhanced anti-corrosive and paint-retaining characteristics comprises the application, by spraying, dipping or otherwise, of a composition in the form of a solution of phosphates which includes an accelerating agent represented by a quantity of tungstate ion and which has a pH value in the range 5.8 to 6.5, and preferably 6.0 to 6.4.