QUANTITATIVE TEST FOR ZINC PHOSPHATE COATING QUALITY

Zinc phosphated steels representing a wide range of salt spray performance were analyzed for coating weight, composition, X-ray structure, morphology, and porosity. Of these factors, apparent coating porosity was the only characteristic that consistently correlated with salt spray performance. An electrochemical test has been developed which measures relative porosity values accurately, rapidly, and directly on zinc phosphated steels. Residual carbonaceous materials bound tightly to the surface of commercial steels need to produce porosity levels of only a few percent in order to reduce drastically the effectiveness of zinc phosphate coatings as a paint base.

• Supplemental Notes:
  • Presented at the SAE Congress and Exposition, Detroit, 27 February-3 March 1978.
• Corporate Authors:

  Society of Automotive Engineers (SAE)

  400 Commonwealth Drive
  Warrendale, PA  United States  15096
• Authors:
  • Zurilla, R W
  • Hospadaruk, V
• Publication Date: 1978

Media Info

• Features: References;
• Pagination: 8 p.

Subject/Index Terms

• TRT Terms: Metal coatings; Performance; Porosity; Steel
• Old TRIS Terms: Zinc phosphates
• Subject Areas: Safety and Human Factors;

Filing Info

• Accession Number: 00395169
• Record Type: Publication
• Source Agency: National Highway Traffic Safety Administration
• Report/Paper Numbers: SAE 780187, HS-025 334U
• Files: HSL, USDOT
• Created Date: Jun 30 1985 12:00AM