ASTM B633 Standard Specification for Electrodeposited Coatings of Zinc on Iron and Steel

Scope:

In ASTM B633 Specification, use to determine material and process requirements for electrodeposited zinc coatings applied to iron or steel articles to protect them from corrosion. It does not cover continuous processes for electrodeposited zinc-coated steel wire or sheet.

Test Procedure:

In ASTM B633 Electrodeposit Coatings must be non-alloyed zinc produced by electrodeposition. For the satisfactory adhesion and corrosion resistance performance of the coatings, the base material must be thoroughly clean. After cleaning the base metal to reduce the risk of hydrogen embrittlement pre-coating treatment and post coating treatment for iron and steel is done. This includes heating the material to relieve stress in pre-coating treatment and baking of material to reduce hydrogen embrittlement in post coating treatment. Then reactive treatment is done in which the electroplated surface is passivated. Supplementary treatments are also given if needed. 

Test Specimen:

Thickness and Adhesion Specimens: If separate specimens for thickness and adhesion tests are required, they shall be strips approximately 25 mm wide, 100 mm long, and 1 mm thick.

Corrosion Resistance Specimens: If separate specimens for corrosion resistance tests are required, they shall be panels not less than 150 mm long, 100 mm wide, and approximately 1 mm thick.

Data: 

Visual Examination: Examined material for compliance with the requirements of lustre and workmanship after electroplating. 

Conclusion:

ASTM B633 gives the detailed specification and importance of electrodeposition of zinc layer on Iron and steel to protect them from corrosion and other defects.