Method for barrel-plating copper and chromium on surface of cold-rolled sheet tinned conductive roller

Abstract

The invention relates to a method for barrel-plating copper and chromium on the surface of a cold-rolled sheet tinned conductive roller. The method is characterized by comprising the following steps of: (1) pretreatment before plating: wiping the conductive roller by using rust removing liquid to activate the conductive roller, and wiping the surface of the roller by using cyanation copper plating bath electrolyte to prevent rusting; (2) copper pre-plating: stopping pre-plating when the thickness of a copper coating reaches 20 microns; (3) thick copper barrel-plating: plating copper by using sulfate electrolyte till the thickness of the coating reaches 1 to 3 millimeters; (4) roughing and peak clipping treatment: wiping a roughed layer by using peak clipping liquid at normal temperature to remove burrs; and (5) hard chromium plating. The method has the advantages that: by adopting the two-step copper plating process of copper pre-plating and thick copper barrel-plating and improving the formula of the copper plating liquid, the copper layer is well combined with the steel without loosening or foaming, the coating crystal is delicate and uniform, and the thickness is improved to HV120 from HV60; the copper layer is plated with the hard chromium after the peak clipping treatment, the plated chromium is firmly combined with the copper matrix, the hardness HV is more than or equalto 950, and the conductive roller has no burrs and is abrasion-resistant and anticorrosive; and the produced conductive roller has stable quality and long service life which reaches over 6 months.

Description

technical field [0001] The invention belongs to the technical field of conductive rolls of a tinning production line in the metallurgical industry, and relates to a method for barrel-plating copper and chromium on the surface of a tinned conductive roll of a cold-rolled plate. Background technique [0002] Tinning of cold-rolled steel sheet is a reprocessing method of cold-rolled steel sheet. Tin-plated steel sheet is widely used in the food industry, such as various cans, etc. When thousands of meters of steel plate are tinned, under the guidance of the driving roller, they automatically enter the processes of degreasing, rust removal, electroplating, reflow, quenching, cooling, coiling, cutting, packaging and so on. During electroplating, anode plates are hung on both sides of each plating tank, a conductive roller is installed in the slot at the upper end, and a sinking roller is installed at the lower end of the bath. During electroplating, the steel plate passes through...

AI Technical Summary

Problems solved by technology

[0003] However, the wear resistance of domestic conductive rollers is not stable enough. Sticking tin will cause the coating to peel off, burrs will easily produce defective products, and the service life is short. Some have to be replaced after only two months. This greatly reduces production efficiency and increases production costs, so that large-scale equipment such as conductive rollers φ475×1200mm and φ610×1300mm used in tinning production lines in my country’s metallurgical industry have long relied on imports