273 results about "Electrogalvanization" patented technology

An electroplating bath, a system, a process for, and the article obtained from, depositing a zinc-nickel ternary or higher alloy, a) zinc ions; b) nickel ions; and c) one or more ionic species selected from ions of Te⁺⁴, Bi⁺³ and Sb⁺³, and in some embodiments, further including one or more additional ionic species selected from ions of Bi⁺³, Sb⁺³, Ag⁺¹, Cd⁺², Co⁺², Cr⁺³, Cu⁺², Fe⁺², In⁺³, Mn⁺², Mo⁺⁶, P⁺³, Sn⁺² and W⁺⁶. In some embodiments, the system includes a divider forming a cathodic chamber and an anodic chamber, with the electroplating bath in the cathodic chamber only. In various embodiments, the zinc-nickel ternary and higher alloys may provide improved properties to the conductive substrates upon which the alloys are deposited.

The invention discloses a method for electroplating alkaline Zn-Ni alloy, comprising the steps of: preparing alkali wash and acid wash, preparing electroplating Zn-Ni alloy plating solution, mechanical grinding, degreasing with organic solvent or water-based detergent, alkali washing, acid washing and electroplating. The invention provides a stable electroplating solution formula and complete electroplating process. The coating electroplated by the method is proved to have good flat surface, uniform coating distribution and alloy distribution, the coating is single gamma-phase, the nickel has a content of 10% to 15%; the coating has superior corrosion resistance, red rust appears on the non-passivated Zn-Ni coating after 1500 hours in a neutral salt spray test; compared with general alkali electroplating solution, the coating has high current efficiency, reaching up to 80% to 90%.

The invention discloses a magnesium alloy with zinc and nickel compound plating layers and a preparation method thereof. A zinc plating layer of the magnesium alloy is taken as a bottom layer with the width between 20 microns and 25 microns, a nickel plating layer is taken as a surface layer, and the total width of the zinc plating layer and the nickel plating layer is less than or equal to 40 microns. The method comprises the following steps: firstly, plating preliminary treatment, i.e. zinc is activated in an acid solution and then soaked in sulphate; secondly, zinc electrodeposition, i.e. after the zinc is soaked in the sulphate in the first step, the zinc layer of the magnesium alloy is electrodeposited; thirdly, nickel bright plating, i.e. the magnesium alloy which is nicely processed in the second step is brightly plated with nickel in a nickel plating solution; fourthly, sodium silicate water solution sealing. With the method, the obtained zinc plating layer is nicely combined with a base body, has uniform width and high corrosion resistance, can be taken as a protective plating layer to be singly used and can be also taken as a transition layer to carry out plating or chemical plating or other protective or decorative platings, and the nickel plating layer obtained from the zinc plating layer by plating is nicely combined with the zinc plating layer and is uniform, exquisite, bright and beautiful.

The invention relates to a method for passivation of zinc and zinc alloy and a chromium-free passivation solution. The passivation method comprises the following steps: soaking a workpiece electroplated with a zinc or zinc alloy layer into a chrome-free passivation solution and then standing in the air; re-soaking the workpiece into the chrome-free passivation solution, and then rinsing and blow-drying; finally drying the workpiece to complete passivation. The chromium-free passivation solution comprises the following components: a titanium salt, an oxidant, a complexing agent, a water-soluble film-forming agent, an accelerator, a Group II metal compound and water. The invention provides a chrome-free passivation solution that can generates blue or flash coating on the deposits of zinc and zinc alloy. The coating is uniform with excellent corrosion resistance, and can delay the appearance of white corrosion products. The passivation method provided by the invention is low in cost, easy in waste liquid treatment, and easy in operation and maintenance.

The invention is a kind of zinc coating and catelectrode electrophoresis compound protection method for neodymium iron boron magnet. The technology point is the combination of catelectrode electrophoresis technology and zinc coating technology, and that it carries on parkerising and passivating process after zinc coating, the process includes following steps: (1) high temperature baking deoil; (2) boiled water sealing (3) deoil; (4) rust cleaning; (5) activating; (6) cold galvanizing; (7) parkerising; (8) passivating; (9) catelectrode electrophoresis. The merits of the invention are: combines the zinc coating and catelectrode electrophoresis, and carries on parkerising process after zinc coating, it enhances the corrosion resisting and water enduring and adhesion propery of neodymium iron boron, the corrosion resisting effect is prominent, and prolongs the operating life to 4-5times.

The invention provides a method for preparing chromium-free passivation solution, and a method for passivating an electrogalvanizing or zinc alloy layer by using the same, and relates to a method for preparing the passivation solution and a using method thereof. The method solves the problems that passivation of hexavalent chromium and trivalent chromium generates pollution, and white rust tested in a salt spray test has short time after the electrogalvanizing or zinc alloy layer is passivated by the passivation solution. The method for preparing the chromium-free passivation solution comprises the following steps: 1, preparing concentrated solution A; 2, preparing concentrated solution B; and 3, regulating pH value after the concentrated solution A, the concentrated solution B and deionized water are mixed, and heating or cooling the mixture to 20 to 60 DEG C to obtain the chromium-free passivation solution. The method for passivating the electrogalvanizing or zinc alloy layer by using the chromium-free passivation solution comprises the following steps: 1, secondarily passivating the electrogalvanizing or zinc alloy layer; and 2, aging the electrogalvanizing or zinc alloy layer to complete passivation on the electrogalvanizing or zinc alloy layer. After the electrogalvanizing or zinc alloy layer is passivated by the chromium-free passivation solution, the electrogalvanizing or zinc alloy layer is subjected to neutral salt spray test, and the white rust does not appears on the surface of a passivated film after 84-120 hours of continuous spraying.

A process for electroplating the inner and outer surfaces of steel tube with Zn is disclosed. It is characterized by that its electroplating liquid has the merits of both alkaline zincate and cyanide used for plating zinc. Its apparatus is characterized by that an auxiliary anode is additionally used inside the steel tube to be plated, that is, its hanger plays the roles of both cathode and anodes. Its advantages are high anticorrosion power of its plated layer and enough thickness of internal plated layer.

The present invention relates to surface treatment of steel plate, and is especially zinc electroplating process to form homogeneous fine zinc layer onto the surface of cold rolled steel plate and environment friendly zirconium-containing no-chromium fingerprint resisting paint for producing zinc electroplating fingerprint resisting steel plate. Cold rolled steel plate is first electroplated with zinc and then coated with fingerprint resisting paint. The production process of fingerprint resisting steel plate features the production process including the first production of zinc electroplated steel plate via vertical anode electroplating process, coating with water-base fingerprint resisting paint with zirconium to replace chromium, and curing through roasting at temperature lower than 125 deg.c to form composite resin film. The electroplated zinc layer has stable and reliable quality and the organic composite resin film has no environmental pollution.

The invention provides a zinc-zinc nickel electroplating method of a neodymium iron boron magnet. The method comprises the steps of grinding and chamfering-deoiling-acid pickling-ultrasonic cleaning-galvanizing (acid)-activation-nickel alloy galvanizing-bright dipping-trivalent chromium passivation-drying. A neodymium iron magnet is prepared by the zinc-zinc nickel electroplating method of the neodymium iron boron magnet; a zinc layer is 2-5 microns; a zinc nickel layer is 5-10 microns; the corrosion resistance is achieved under the neutral salt mist environment for 2h and the environment of 40 DEG C and 90% of humidity for 168h; the binding force of the neodymium iron boron magnet can satisfy the requirement of falling by 1.8 m*30 times; the magnetic reducing loss is not increased (not more than 6%); the hexavalent chromium problem is solved (hexavalent chromium is not more than 1000 ppm); and the cost is lower than that of nickel electroplating of copper nickel.

The invention relates to electrolytic plating assistant for hot dip galvanizing of a steel wire. Electrolytic plating assistant comprises the following components: 30-220 g/L of zinc chloride, 0-150 g/L of potassium chloride, 0-150 g/L of sodium chloride, 2-90 g/L of ammonium chloride, 0-100 g/L of boric acid, 0-70 g/L of acetic acid, 1-25 g/L of sodium fluoride, 2-50 g/L of cerium chloride, 0-50 g/L of potassium fluozirconate, 0-50 g/L of methanol, 0.5-20 g/L of hydrogen peroxide and the balance of water. The electrolytic plating assisting method comprises the following steps: washing with alkali, removing oil, washing with water, washing with acid to remove rust, washing with water, activating with weak acid, electrolyzing to assist plating, drying, and purifying the electrolytic plating assistant. The method can reduce the generation of AlCl3, prevent skip plating and reduce the generation of smoke dust. The electrolytic plating assistant has the characteristic of relatively high melting point, and thus, can increase the drying temperature and shorten the drying time. The dried plating assistant has the characteristics of low brittleness, high compatibility with electrogalvanizing, and low tendency to shedding.

The invention discloses a production method of a cold-rolled steel plate for electro-galvanization. The steel plate is smelted according to components. The production method comprises the following concrete technological steps: (1) pretreating liquid iron; (2) smelting in a rotary furnace; (3) finely tuning alloy; (4) refining in an RH furnace; (5) continuously casting; (6) performing hot rolling; (7) rolling; (8) performing cold rolling; (9) continuously annealing; (10) flattening. By precisely controlling the components in the steel and being combined with a production process of the cold-rolled steel plate for electro-galvanization, the production method disclosed by the invention can be used for obtaining the cold-rolled steel plate which is 150 to 40Mpa in yield strength, higher than 270MPa in tensile strength, larger than 37% in percentage elongation, capable of satisfying the requirements of deep drawing and molding, good in plate form and surface quality (above FC) and capable of satisfying the requirements of electro-galvanization and subsequent passivation and anti-fingerprint treatment; the surface quality of the steel plate for electro-galvanization can be improved; the steel plate for electro-galvanization is enabled to have the good plate form.

A method for preparing metallic electrode with nano-pore structure by electrochemical alloying/dealloying process is provided. The method comprises: firstly adding a zinc salt into an organic solvent and heating to allow dissolution; then inserting a metallic electrode as working electrode, a zinc sheet as auxiliary electrode and an inert metal as reference electrode; electrochemically applying a circulatory potential scanning, wherein a Zn coating is formed on the surface of Au substrate during cathode potential scanning, and the deposited Zn reacts with Au substrate to form Zn-Au alloy with the solution temperature rise during the electrogalvanizing; and finally dissolving Zn from the alloy by the anode potential scanning and dealloying. The method can produce the metallic electrode with nano-pore structure, which has extremely-high roughness after treatment, substantially increase the effective response area of metallic electrode, and greatly improve the sensitivity and catalytic efficiency of metallic electrode in application. The invention has the advantages of simple operation, easily-accessible raw material, low cost, no toxicity, and no environmental pollution; and is used in analysis, catalysis and sensor fields.

The invention discloses a plating metal fastener, which comprises the following steps: plating copper, nickel and zinc; sleeving metal fastener in the elastic pad; rotating metal fastener in the ferric board hole with two thirds force as standard torque until fastening tightly; placing tested screw in the refrigerator at -5 deg. c for 24h; fetching to restore to normal temperature; dropping ferric board vertically from one meter height; judging whether the end breaks; satisfying the standard if not breaking.

The invention discloses a production method for a zinc electroplated baked hardened steel plate for an automobile outer plate and belongs to the field of cold-rolled deep-drawn zinc electroplating automobile steel. The production method comprises the following preparation steps that (1) constituent selection of the zinc electroplated baked hardened steel plate is conducted; (2) a plate blank is obtained through smelting and casting; (3) hot rolling is conducted after conventional heating; (4) conventional water cooling is conducted to the coiling temperature, and coiling is conducted; (5) cold rolling is conducted; (6) continuous annealing is conducted; (7) flattening is conducted; (8) conventional alkali washing, brushing, electrolytic degreasing and rinsing are conducted; and (9) zinc electroplating is conducted through a gravity method. According to the production method, the steel plate prepared through a conventional production technique is good in forming performance and baking and hardening performance, natural aging is avoided even if the steel plate is placed at the room temperature for months, and the performance is stable.

Disclosed is steel with the extending rate larger than or equal to 44 percent for an electrogalvanizing automobile outer plate. The steel comprises, by weight, C smaller than or equal to 0.0018 percent, Si smaller than or equal to 0.015 percent, Mn ranging from 0.05 percent to 0.18 percent, P smaller than or equal to 0.015 percent, S smaller than or equal to 0.010 percent, Ti ranging from 0.02 percent to 0.03 percent, Nb ranging from 0.03 percent to 0.05 percent, Als ranging from 0.02 percent to 0.05 percent and N smaller than or equal to 0.003 percent. The production steps comprise smelting and continuous casting to form a billet, hot rolling, reeling, cold rolling, continuous annealing and cooling. The method comprises the steps of slow cooling and then rapid cooling, finishing, alkaline washing, brushing, electrolytic degreasing and rinsing, and electrogalvanizing through a gravitational method. The steel has the advantages of being good in surface quality, stable in performance, free of aging, excellent in forming performance, excellent in welding performance and the like; according to the material object performance (perpendicular to the rolling direction) of a finished electrogalvanizing super-deep punching board DC07+ZE for the automobile outer plate, the yield strength is 100 MPa to 150 MPa, the tensile strength is 250 MPa to 310 MPa, the plastic strain ratio r<90> is larger than or equal to 2.3, the work-hardening exponent n<90> is larger than or equal to 0.25, and the extending rate A80 mm is larger than or equal to 44 percent.

The invention discloses an alkaline non-cyanide zinc plating nickel alloy plating solution and an electroplating process thereof. The plating solution is prepared with hydantoin or a hydantoin derivative as a main coordination agent by adding an auxiliary coordination agent, zinc sulfate, nickel sulfate, potassium carbonate and water. The plating solution comprises 20 g-400 g/L of the main coordination agent, 5 g-300 g/L of the auxiliary coordination agent, 5 g-200 g/L of the zinc sulfate, 1 g-150 g/L of the nickel sulfate and 5 g-435 g/L of the potassium carbonate. The electroplating process of the plating solution comprises the steps of substrate pretreatment and zinc-nickel alloy electroplating. A constant current electroplating mode is adopted for zinc-nickel alloy electroplating. The electric current density is 0.5 A-5 A/dm2. The temperature of the plating solution is 30 DEG C-60 DEG C. The distance between a cathode and an anode is 0.5 cm-25 cm. The stirring speed of the plating solution is 0 rpm-3000 rpm. The electroplating time is 1 min-120 min. According to the plating solution and the electroplating process thereof, the hydantoin or the hydantoin derivative serves as the main coordination agent for the first time, and zinc-nickel alloy with the nickel content of 10 wt.%-13 wt.% is obtained through electro-deposition by using the main coordination agent and the auxiliary coordination agent in a combination mode. An obtained coating is good in corrosion resistance. The stability of the plating solution is improved immensely compared with using of a single coordination agent.

The inventions are sorts of magnesium, magnesium alloy which is compound plating coat of high anti corrosion, and their preparation technics. Compound plating coat based on the chemical nickel coat, the thickness of which is between 20 and 25 micron. The callow of it is electrolytic zinc plating and nickel alloy, the thickness of which is between 8 and 10 micron. The following is the preparation craftwork: the chemical nickel plating of magnesium alloy adopts the standard B480-88 of American material experimentation association. Plating time is between 1.4 and 2 hours. The coating thickness is between 20 and 25 micron. The content of phosphor in the plating layer is 9-12%; electrolytic zinc plating and nickel alloy: the plating liquid of it and technics conditions are followed: sodium hydroxide 8-15%, zinc oxide 2-5%, nickelous chloride 0.5-3%, ethylamine 2-4%, tiethanolamine 2-4%, nylander reagent 0.5-3%, DE0.2-0.8%, sodium dodecanesulphonate 0.01-0.1%, the overmeasure is water. Curl density is 0.5-5A/dm2. Plating time is 30 minutes. The content of nickel in the plating coat is 13-18%; It adopts black passivation technics of zinc and nickel alloy. The thickness of plating coat of this invention doesn't exceed 35 micron.

The invention relates to a galvanized layer chromium-free passivant and a use method thereof, wherein the passivant comprises a passivation film-forming agent, an adhesion promoter, an emulsifying agent, acetone and an aqueous solution, when using, the chromium-free passivant and water are diluted according to the proportion of 1: 4 and then put in a passivation tank, a galvanized part is bright-dipped through diluted acid at a plating bath outlet of a continuous electrogalvanizing production line, then enters into the passivation tank under the normal temperature for passivating 5-20 seconds, taken out, flushed with water and dried by hot air. The galvanized layer chromium-free passivant forms a passivation film on the metal surface by reasonably utilizing certain chromium-free organic acids, and the like, has corrosion inhibition property, adopts resin as the promoter as well as the acetone and water as solvents, is prepared by adopting a compound method, free of chromium and used for carrying out passivating treatment instead of chromate and chromium trioxide and eliminates hazards to the environment and the human body from chromium pollution.

The invention provides a blackening preventing electrogalvanized steel plate and a method for manufacturing the steel plate. The surface of an electrogalvanized layer of the steel plate is provided with a nickel layer with the thickness of 0.05 to 10 mg/m <2>; and lubricating oil is coated on the external surface of the nickel layer and the thickness of the lubricating oil is 0.3 to 3 g/m <2>. Themethod for manufacturing the steel plate comprises the step of: soaking the electrogalvanized steel plate in an acid solution containing 0.5 to 50 g/L of Ni <2+> for more than one second, or performing cathodic electrolysis processing on the electrogalvanized steel plate through the acid solution containing the Ni <2+> for more than 0.5 seconds. After being added with nickel, the steel plate caneffectively prevent the blackening of the surface of the steel plate and simultaneously has good stamping forming performance and coating performance.

The invention relates to a metal wiredrawing composite steel plate and a preparation method thereof. A base material of the metal wiredrawing composite steel plate is a hot galvanizing steel plate or an electro-galvanizing steel plate, a straight grain wiredrawing structure is formed on the front side of the base material through wiredrawing by using a metal surface wiredrawing machine, and a transparent fingerprint-resistant paint layer is formed on the straight grain wiredrawing structure through roller coating. During manufacturing, the method comprises the following steps of: performing wiredrawing process treatment on the front side of the base material by using the metal surface wiredrawing machine; performing degreasing cleaning on the base material subjected to the wiredrawing process treatment to remove oil stains on the surface; performing surface passivation in a sprinkling mode after the degreasing cleaning to form colorless paint bottom passive films on the front side and the back side of the base material, and drying in a drying oven; painting a back paint on the back side of the base material through roller coating at normal temperature after the passivation, and drying in the drying oven; painting a transparent fingerprint-resistant paint on the front side of the base material which is subjected to wiredrawing, degreasing cleaning and passivation; and coating a protective film on the surface of the transparent fingerprint-resistant paint layer. By directly treating the hot galvanizing steel plate or electro-galvanizing steel plate by using a wiredrawing process, and coating a transparent paint layer on the hot galvanizing steel plate or electro-galvanizing steel plate, an appearance effect of imitation stainless steel is achieved.

The invention discloses an electroplating process of an electroplated metal fastener. The electroplating process comprises the steps of copper electroplating, nickel electroplating and zinc electroplating in sequence, specially as follows: (1) preparing the solution for the copper electroplating process: 135mg/L of copper sulfate, 90mg/L of malic acid, 210mg/L of citric acid, 40mg/L of potassium citrate, 20mg/L of sodium hypophosphite, and 15mg/L of glucose, wherein the process conditions are as follows: the current density is 1.5A/dm<2>, an anode is of a 0.3%-phosphorus-containing copper plate, the area ratio of the anode to the cathode is 2:1, the temperature is 20-25 DEG C and the time lasts for 8 minutes; (2) electroplating nickel; and (3) electroplating zinc. By adopting the electroplating process, the problem of hydrogen embrittlement can be solved; the electroplated copper, the electroplated nickel and the electroplated zinc all adopt specific solution, the electroplated layer has no burr and is less rough, the surfaces of the electroplated layers can not produce pin holes, the phenomenon of leaking electroplating can not occur, the electroplated layers are combined more firmly, the electroplating deposition velocity is fast, and the corrosion resistance property is stronger.