Zinc Chromate Plating Specifications

Trivalent yellow meets automotive and rohs specifications.

Zinc chromate plating specifications. Astm b633 sc1 type ii scope this specification covers electrodeposited zinc coatings as applied to steel copper brass and bronze parts to protect them from corrosion. Chromate conversion coating or alodine coating is a type of conversion coating used to passivate steel aluminium zinc cadmium copper silver titanium magnesium and tin alloys. Techmetals also offers r d optical coatings medical coatings large id od grinding areas with 20 ton capacities. We also offer metal plating solutions to additional specifications such as ams mil astm sae and customer specifications.

We are getting poor coverage on the as cast surface of some steel castings using a yellow zinc chromate. Zinc plus yellow hexavalent free chromate part suffix zc. Specifications thickness comments qq n 290a class 1 grade e class 1 grade f class 1 grade g 0006 min 0004 min 0002 min. I am in need of as much information as i can get about the chemical composition of coatings.

Zinc plating plus yellow chromate coating on steel sae j81 zinc plate and yellow zinc dichromate coating to meet ford wsb m10p10 a3 and wsd m1p85 a2 on aisi 12l14. Color can vary from colorless to iridescent yellow brown. A discussion started in but continuing through 2018. Steel parts requiring embrittlement relief after plating are baked according to industry standards.

Coatings shall be continuous free from. Plating specifications general information page 8 reference only april 2018 chemical film chromate mil c 5541 coatings for aluminum zinc silver and cadmium. Astm b 633 type ii vs. Specs for chromate zinc coatings 2002 q.

Below is a list of specifications that are most often provided by techmetals. Zinc plating with clear passivation gives all the same advantages of any other zinc plating particularly the addition of considerable corrosion resistance. Specifically for the following coatings. Advantages of clear zinc plating.

Springs having a hardness over rc 40 must be given anafter plating baking of 375 25 f for 3 hours. As a rule the darker the chromate the more corrosion resistant the finish with the same amount of plated thickness. P 1265 the coating serves as a corrosion inhibitor as a primer to improve the adherence of paints and adhesives as a decorative finish or to preserve electrical conductivity. We also currently do hexavalent and trivalent yellow zinc plating.

Zinc should be deposited directly on the base metal nickelis permissible undercoat if base metal is a corrosion resisting steel parts having a hardness greater that rc 40 must be given a heat treatmentprior to plating. Yellow can be used as is or as a paint base.