Application: Chrome Piston rod is mainly used in hydraulic pneumatic, engineering machinery, automobile manufacture with the piston rod, guide pillar plastic machinery, packaging machinery, printing machinery, roller, textile machinery, transportation machinery with axis, linear motion with the linear optical axis.

I. process introduction.

The piston rod is hard chromium plating on steel substrate surface coated with a thick layer of chromium plating and its thickness is in commonly 10 to 30 microns , using the characteristics of chromium improve parts’ performance ,such as hardness, wear resistance, heat resistance and corrosion resistant .

The process features of hard chrome plated piston rod:

1) the cathode current efficiency is as high as 25% ~ 35%, and the deposition rate is very fast.

2) high hardness (900 ~ 1200HV), uniform and dense network cracks, good abrasion resistance;Microcracks can be produced, and the number of microcracks can reach 800-2000 pieces/cm (according to the need), and improve the anti-corrosion ability.

3) good dispersion ability of the plating bath, uniform thickness of the coating, not easy to produce the phenomenon of rough blister tumor, and the appearance of chromium layer is bright and smooth;

4) the coating has strong bonding strength with the substrate, and the pretreatment is similar to the traditional technology, and the operation is easier than the traditional process;

5) the content of trivalent chromium in the bath is allowed to be wide, and it usually does not need to discontinue electrolysis for trivalent chromium;

6) the plating solution contains no fluoride, no rare earth elements, and no corrosion of the workpiece without low power.

2. Process flow.

1). Process flow of hydraulic piston rod.

Connecting rod using 35 steel, processing technology: cold-drawn forming a turning a continuous medium frequency induction hardening, a cylindrical grinding, a fine grinding cylindrical a fine grinding cylindrical shearing section.at finishing a plating chromium to hydrogen tempering shearing section.at fine grinding.In order to improve the surface quality and corrosion resistance of piston rod, super finishing process was added before chrome plating.

2). Piston rod plating process.

Inspection before plating - pack hanging fixture - chemical degreasing, electric lift oil - water - activation pickling - water washing- the moment, the piston rod chromium plating, recycling water - water washing - unloading hanging fixture - inspection