Zinc-nickel alloy electrodeposition process The formation of zinc-nickel alloy plating layer in the plating solution composed of zinc salt, nickel salt, conductive salt and additive, two kinds of metals with large potential difference between zinc (-01763V) and nickel (-0125V) Abnormally co-deposited as a single C-phase zinc-nickel alloy coating at the same polarization potential. After passivation treatment, a highly corrosion-resistant zinc-nickel alloy plating layer is obtained. In order to meet different corrosion resistance and appearance requirements, a zinc-nickel alloy coating which is passivated by color, white or black can be obtained. Electrodeposition process pretreatment y degreasing y cleaning y derusting y cleaning y activation y water washing y electroplating zinc nickel alloy y three-stage countercurrent rinsing y passivation y washing y dry y test y classification packaging. Electroplating bath and process conditions plating solution and process conditions. Nickel content and passivability of the coating. The zinc-nickel alloy coatings studied in this process were simultaneously measured by S250Mk3 scanning electron microscope, chemical gravimetric method and spectrophotometric colorimetric method. The measurement results of the same batch of samples were basically the same. The coatings with different zinc-nickel contents are controlled according to different corrosion resistance and passivation color requirements. The coating is resistant to thermal shock. The zinc-nickel alloy coating sample is heated to a set temperature in an oven, and immediately immersed in room temperature water for chilling after taking out, and the coating is not pelt, non-bubble, or detached, and the thermal shock of the zinc-nickel alloy coating is investigated. performance. Test results The thermal shock resistance temperature of zinc-nickel alloy can reach bubbling and peeling when the temperature is 250e.300350e, but the sample still has no bubbling or peeling when slowly cooling. Zinc-nickel alloy coating corrosion resistance. Zinc-nickel alloy coating provides cathodic protection for fasteners and has excellent corrosion resistance <2>. The corrosion current density of the zinc-nickel alloy coating was measured by weak polarization in a 5% NaCl solution, and the neutral salt spray experiment was used to verify the experiment. The relationship between the corrosion current density of zinc-nickel alloy coating and hot-dip galvanizing layer as a function of time is shown. The test confirmed that the corrosion resistance of the zinc-nickel alloy coating is related to the nickel content of the coating, and the zinc-nickel alloy coating of Zn-13%Ni has the best corrosion resistance. The equipment used in the test was CMB-1510B instantaneous corrosion rate measuring instrument and DF-27 type multi-purpose corrosion test box. Zinc-nickel alloy coating, hot dip galvanic corrosion current density as a function of time 1) hot-dip galvanizing in brine; 2) hot-dip galvanizing in tap water; 3) zinc-nickel alloy in brine; 4) zinc-nickel alloy in tap water 5 Application situation Zinc-nickel alloy electroplating technology is stable in process, mature in technology, and all equipment and raw materials used are locally localized. It has excellent corrosion resistance and relatively low economic cost. It has huge economic benefits and broad promotion prospects. It is an ideal technology to replace traditional electro-galvanizing and hot-dip galvanizing. On-site hanging test at the Sanhejian Coal Mine of Xuzhou Mining Bureau and Yaoqiao Coal Mine of Datun Coal and Electricity Company has achieved good results. Has been successfully applied to Henan, Shandong, Liaoning, Gansu, Hebei, Jiangsu and other mines of various standard fasteners, U-bolts, washers, anchors, node clips, etc. more than 150 tons of electroplated zinc-nickel alloy anti-corrosion, use 34 The effect is good and there is no rust. In addition, zinc-nickel alloy coatings have also been applied in automotive fasteners, guardrails, household appliances and electronic control equipment. Conclusion (1) The corrosion current density of zinc-nickel alloy coating in the medium is much lower than that of electro-galvanized layer and hot-dip galvanized layer, and the corrosion life is long. (2) The low corrosion rate and high corrosion resistance of zinc-nickel alloy coating will be the development direction of long-term corrosion protection of steel parts with anodic coating. Its development trend is to replace electroplating zinc, hot dip galvanizing and cadmium plating. (3) Zinc-nickel alloy coating is the preferred method for long-term corrosion protection of fasteners in mine environment and other industrial environments. Round Bath Spout,Freestanding Round,Round Wall Mount Water Spout,Columnar Brass Spout Moon Shower Sanitaryware Co.,Ltd , https://www.moonshowerglobal.com