Classifications

• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C22/00—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
  • C23C22/05—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions
  • C23C22/06—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6
  • C23C22/07—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6 containing phosphates
  • C23C22/08—Orthophosphates
  • C23C22/12—Orthophosphates containing zinc cations
• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C22/00—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
  • C23C22/05—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions
  • C23C22/06—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6
  • C23C22/07—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6 containing phosphates
  • C23C22/08—Orthophosphates
  • C23C22/12—Orthophosphates containing zinc cations
  • C23C22/13—Orthophosphates containing zinc cations containing also nitrate or nitrite anions
• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C22/00—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
  • C23C22/05—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions
  • C23C22/06—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6
  • C23C22/07—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6 containing phosphates
  • C23C22/08—Orthophosphates
  • C23C22/18—Orthophosphates containing manganese cations
  • C23C22/182—Orthophosphates containing manganese cations containing also zinc cations

Definitions

• the invention relates to a method for facilitating the cold forming of iron materials by applying a phosphate coating by means of an aqueous, acidic phosphating solution which contains zinc ions and hydroxylamine as accelerators.
• Phosphate coatings are usually applied to metal surfaces in order to improve their corrosion resistance and to increase the adhesion of the paint that is subsequently applied. Phosphate coatings also serve to facilitate cold forming, where they themselves act as a "lubricant" by helping to avoid seizing or welding of material and tools, or by binding a subsequently applied lubricant so that it is practically not removed during the forming process. In particular, the latter ability is of particular importance because only the combination of the phosphate coating and the lubricant enables multiple or severe cold working, possibly without a new intermediate treatment with lubricant.
• phosphate coatings Numerous methods are known to facilitate cold working by applying phosphate coatings. They can belong to the category of "layer-forming” as well as - albeit with considerably less importance - the category of “non-layer-forming” processes.
• Layer-forming here means the formation of phosphate coatings by means of phosphating solutions which, in addition to the phosphate ions, also supply the majority of the cations for coating formation.
• the cations of the phosphate coating usually come from the treated metal itself, ie the phosphating solution essentially only provides the phosphate ions.
• US Pat. No. 2,298,280 describes a coating solution which contains an acidic phosphate, such as zinc or manganese phosphate, and hydroxylamine as an accelerator.
• an acidic phosphate such as zinc or manganese phosphate
• hydroxylamine as an accelerator
• the phosphate layer formation aims to improve the corrosion resistance and the paint adhesion.
• the patent does not contain any reference to the layer thickness of the phosphate layer produced or to the suitability of this layer for facilitating the cold deformation.
• the zinc and manganese concentrations mentioned, for example are so low that the usability of these phosphating solutions for the relief of cold working is extremely doubtful.
• a disadvantage of the known, especially the aforementioned The method is that the phosphate coatings produced do not have the thickness required to facilitate cold working and the adhesion is too low.
• US Pat. No. 2,743,204 discloses a "layer-forming" phosphating for the production of phosphate coatings, which among other things. is also intended to facilitate cold forming, known. It describes phosphating solutions for the treatment of iron, steel, zinc and aluminum with zinc or manganese as layer-forming cations, which can contain a wide variety of accelerators. Nitrite, chlorate, bromate, sulfite, nitro organic compounds such as nitrobenzenesulfonate, picric acid, and iodate, hydroxylamine and nitrate are mentioned. With regard to the achievable layer weights, chlorate is particularly emphasized. It has obviously not been recognized that hydroxylamine is particularly important in this regard. However, the zinc content of the phosphate layers thus obtained is too low to form the desired zinc stearates in sufficient quantity as a lubricant for cold forming in the subsequent treatment with soap solutions.
• the object of the invention is to provide a process for facilitating the cold forming of ferrous materials which does not have the disadvantages of the known processes, in particular improves the subsequent formation of zinc stearates by a high zinc content and leads to thick, adherent phosphate coatings with simple process control.
• the object is achieved by designing the method of the type mentioned at the outset in accordance with the invention in such a way that the iron materials are brought into contact with a phosphating solution which calculates 7.5 to 75 g / l of zinc ions and 5 to 75 g / l of nitrate ( as NO3) contains 0.1 to 10 g / l hydroxylamine.
• Phosphating solutions with hydroxylamine as an accelerator in combination with comparatively high concentrations of zinc are particularly suitable for the production of Phosphate coatings designed to facilitate cold working. Thanks to their excellent adhesion to the iron material as such, but especially in combination with conventional lubricants, the phosphate coatings are effective even with the most severe deformations. In addition, the process is not adversely affected even in the presence of ferrous or ferric ions in the solution.
• An additional advantage of the method according to the invention therefore lies in being able to bring the iron materials into contact with a phosphating solution, the iron ion content of which can be up to 25 g / l.
• Cold deformation in the sense of the present method are all deformation processes into which the workpiece is introduced at a temperature ranging from approximately ambient temperature to approximately 100 ° C. and in which an increase in temperature of the workpiece is the result of the deformation work performed.
• Such methods are, for example, extrusion, upsetting, wire or tube drawing.
• the method is particularly suitable for workpieces made of steel with a carbon content below 1% by weight, especially with a carbon content of approximately 0.05 to 0.6% by weight. Compared to known processes, it is also suitable for higher-alloy steels, which generally also have a higher hardness.
• the hydroxylamine to be added to the phosphating solution can be of any commercial type. Storage-stable salts or complex compounds, which are predominantly in the form of hydrate, are preferred. Hydroxylamine sulfate, also called hydroxylammonium sulfate [(NH2OH) 2. H2SO4], is a particularly suitable compound.
• the assumption about the particularly advantageous effect of the hydroxylamine as an accelerator is that the zinc content incorporated in the phosphate coatings is particularly high.
• This high zinc content increases the lubricating properties of the phosphate crystals themselves.
• the increased zinc content greatly increases the reactivity to a subsequently applied lubricant, especially when it comes to fatty acids or soaps.
• the preferred zinc content of the phosphating solution is 7.5 to 55 g / l and is preferably in the range of 10 to 30 g / l.
• a preferred embodiment of the invention provides for the use of a phosphating solution which additionally contains manganese ions in an amount of up to 20 g / l.
• the phosphate content of the phosphating solution must be based on the content of the layer-forming cations. It is generally 5 to 80 g / l, preferably 10 to 70 g / l (calculated as PO4).
• the invention provides for a phosphating solution to be used which contains nitrate as an additional accelerator.
• the nitrate content should preferably 30 to 70 g / l (calculated as NO3). It is advisable to adjust the weight ratio of nitrate to phosphate to a value in the range from 0.3 to 6, preferably 0.5 to 5, but in particular 0.9 to 4.5 (calculated as the weight ratio NO3: PO4).
• the phosphating solution used in the process according to the invention has the ability to form phosphate coatings with a high zinc content and still tolerate comparatively high iron contents.
• the concentration of iron ions in the form of ferrous or ferric ions can be up to 25 g / l, so that the process can also be carried out on the iron side without any loss.
• a further advantageous embodiment of the invention provides for the iron materials to be brought into contact with a phosphating solution which additionally contains nickel ions, preferably in an amount of 0.05 to 1 g / l, in particular 0.1 to 0.5 g / l. contains.
• the phosphating solutions can expediently be used at a temperature of 54.4 to 96.1, in particular 71.1 to 87.8 ° C. Their pH is about 1.8 to 2.5 at the above temperatures.
• the application of the phosphating solution is carried out in the usual way, preference is given to immersion or flooding, in particular immersion.
• the contact time during the immersion treatment is about 0.5 to 30 minutes, preferably 5 to 15 minutes.
• the workpieces are pretreated before phosphating in the usual way, such as by cleaning, pickling, rinsing or activating.
• a water rinse or a rinse with a weakly alkaline solution e.g. Contains borax, nitrite, triethanolamine or mixtures thereof.
• the iron material can then be subjected to cold working.
• a lubricant that is customary in cold-forming processes is preferably also applied. This can be done immediately after coating or after rinsing.
• the lubricant can also be applied immediately before the deformation, if necessary also between the deformation steps. If the purpose of the formation of zinc soaps is with the application of lubricant, care must be taken to ensure that the phosphate coating is sufficiently moist for the reaction.
• Soaps, oils and other auxiliaries for cold working or emulsions of fatty acids or soaps, in particular with 8 to 18 carbon atoms in the acid anion, can be applied as lubricants.
• fatty acids and soaps an emulsion containing 3 to 15% by weight should be used. Because of the reaction with the cation of the phosphate coating already mentioned above, sodium and / or Potassium soaps, especially stearates, are particularly advantageous.
• drying can be carried out in a conventional manner after the final treatment or between individual treatment stages - with the above-mentioned limitation in the formation of zinc soap.
• the iron material can then be subjected to cold working immediately or after intermediate storage.
• a phosphating solution was prepared which contained and had 60 total acid points in a 5.0 ml sample (total acid points equal to consumption of 0.1 N NaOH in ml when titrated against phenolphthalein as an indicator).
• the solution was heated to 82.2 ° C and with 5 g / l hydroxylamine sulfate transferred.
• the materials treated as above were then rinsed with a weakly alkaline solution and provided with a lubricant containing sodium stearate. It was then dried and the excess soap left on the workpiece.
• the workpiece was then subjected to conventional cold forming, for example an extrusion treatment.
• the results were excellent and far superior to those achieved using standard phosphating processes.
• a concentrate A was formulated for the preparation of a phosphating solution 210 g of this concentrate were then diluted to 1 1 ready-to-use phosphating solution.
• This supplemental concentrate can be used if the ratio of total acid to free acid in the working phosphating solution rises above the desired value. If the ratio in the working phosphating solution falls below the desired value, concentrate A can be added.

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• Chemical & Material Sciences (AREA)
• General Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Mechanical Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Lubricants (AREA)
• Chemical Treatment Of Metals (AREA)
• Mounting, Exchange, And Manufacturing Of Dies (AREA)
• Forging (AREA)
• Transition And Organic Metals Composition Catalysts For Addition Polymerization (AREA)
• Preparation Of Compounds By Using Micro-Organisms (AREA)
• Blow-Moulding Or Thermoforming Of Plastics Or The Like (AREA)
• Non-Silver Salt Photosensitive Materials And Non-Silver Salt Photography (AREA)
• Materials For Medical Uses (AREA)
• Pharmaceuticals Containing Other Organic And Inorganic Compounds (AREA)
• Treatments Of Macromolecular Shaped Articles (AREA)
• Glass Compositions (AREA)
• Non-Reversible Transmitting Devices (AREA)

Priority Applications (1)

Applications Claiming Priority (2)

Publications (3)

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Family Applications (1)

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• 1985
  • 1985-11-27 CA CA000496351A patent/CA1257527A/en not_active Expired
  • 1985-11-29 ZA ZA859171A patent/ZA859171B/xx unknown
  • 1985-11-29 AU AU50522/85A patent/AU577424B2/en not_active Ceased
  • 1985-12-11 EP EP85115775A patent/EP0186823B1/de not_active Expired - Lifetime
  • 1985-12-11 DE DE8585115775T patent/DE3582873D1/de not_active Expired - Fee Related
  • 1985-12-11 DE DE19853543733 patent/DE3543733A1/de not_active Withdrawn
  • 1985-12-11 AT AT85115775T patent/ATE63575T1/de active
  • 1985-12-18 ES ES550112A patent/ES8703943A1/es not_active Expired
  • 1985-12-20 GB GB08531408A patent/GB2169620B/en not_active Expired
  • 1985-12-20 JP JP60287615A patent/JPS61157684A/ja active Granted

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