Tire nut deep blind hole plating and coating process

Abstract

The invention discloses a tire nut deep blind hole plating and coating process. The process comprises the steps that firstly, the parts are sequentially subjected to pretreatment including thermokalite oil removing, thermokalite oil removing, electrolytic oil removing, acid pickling, electrolytic oil removing, excitation, pre-electroplating, stripping and electroplating; the two passes of thermokalite oil removing ensure that oil stain inside blind holes is cleaned away; stripping is conducted after pre-electroplating, and oxide skin inside the blind holes is stripped; additives are added intoelectroplating liquid medicine during electroplating; residual water in the blind holes of the electroplated parts is thrown away through rotation of a production line roller and a discharging centrifugal drier; then dehydrogenation baking is conducted, and residual water inside the blind holes is evaporated through high-temperature baking; and finally, passivation and closing are conducted. Theproblems that the covering power of zinc-nickel alloys is not sufficient, and consequently no clad layer exists in the blind holes and the blind holes rust easily are solved, and the process has the beneficial effects that oil stain and oxide layers in the blind holes are effectively removed, uniform zinc-nickel clad layers are plated, the interiors of the blind holes are prevented from rusting, and the first pass yield of products is improved to be 95% or above.

Description

technical field [0001] The invention relates to the field of manufacturing fasteners for automobiles, and relates to a surface treatment method for fasteners, in particular to a deep blind hole coating process for tire nuts. Background technique [0002] Tire nuts are relatively common parts on vehicles that may be disassembled frequently. At the same time, they are also part of automotive safety components. The anti-corrosion ability of the surface treatment of the nuts will directly affect the performance and safety factor of the vehicle. The hole structure and the blind hole are deep, which makes the electroplating in the blind hole more difficult, and the hole is prone to rust. In the traditional electroplating process, the deep plating performance of zinc-nickel alloy electroplating is worse than that of galvanizing, and there is no coating phenomenon for some deep hole parts. Using the traditional pretreatment process: hot alkali degreasing→electrodegreasing→pickling→...

AI Technical Summary

Problems solved by technology

Using the traditional pretreatment process: hot alkali degreasing→electrodegreasing→pickling→electrodegreasing→activation→electroplating, it was found that the oil and scale in the blind holes could not be completely removed, and more than 80% of the inner holes of the parts were black There is no coating, and there is iron slag residue on the internal thread of the blind hole

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