Coatings of Zinc Mechanically Deposited on Iron and Steel

ASTM B695-04: Standard Specification for Coatings of Zinc Mechanically Deposited on Iron and Steel

For engineers and designers seeking robust corrosion protection for iron and steel components, understanding the ASTM B695-04 standard is essential. This authoritative specification provides a comprehensive framework for applying zinc coatings via mechanical deposition, ensuring reliable performance in demanding environments.

What is B695-04?

ASTM B695-04, "Standard Specification for Coatings of Zinc Mechanically Deposited on Iron and Steel," is an industry-leading standard developed by ASTM International. Its primary purpose is to define the requirements for uniform zinc coatings applied to ferrous substrates through a mechanical plating process, offering superior corrosion resistance and performance characteristics.

Scope & Purpose

This standard governs the mechanical deposition of zinc coatings on iron and steel basis metals, specifying requirements for various coating thicknesses up to 107 micrometers. It details the process, including surface preparation, the mechanical deposition of zinc, and optional supplementary treatments like chromate conversion coatings. The standard does not cover electroplated zinc coatings or hot-dip galvanized coatings.

Who Must Comply?

• • Primary audience: Materials Engineers, Quality Control Inspectors, Production Managers, Process Engineers, and Plating Technicians.
• • Industries affected: Manufacturing, Automotive, Aerospace, Construction, and Hardware industries.
• • Compliance nature: Typically voluntary, but often mandated by project specifications, purchase orders, or regulatory requirements.
• • Enforcement: Compliance is typically verified through internal quality control processes, customer inspections, and third-party audits.

Key Requirements Overview

• • The standard requires the zinc coating to be uniform in appearance, free from defects like blisters or pits that could compromise its protective function.
• • Professionals must ensure the coating covers all significant surfaces, including intricate areas like thread roots and edges.
• • Key provisions include specific classes of coating thickness, measured in micrometers, to meet varying corrosion resistance needs.
• • The specification details the mechanical deposition process, which involves tumbling parts with zinc powder, impact media, and promoters to drive zinc onto the substrate.
• • Optional supplementary treatments, such as chromate conversion coatings for enhanced corrosion resistance and color coding, are also defined.

Related Standards & References

ASTM B695-04 works in conjunction with other proven ASTM standards. For instance, ASTM B117 (Practice for Operating Salt Spray (Fog) Apparatus) is frequently referenced for corrosion resistance testing to validate coating performance. Additionally, standards like ASTM A153/A153M (Specification for Zinc Coating (Hot-Dip) on Iron and Steel Hardware) provide context for alternative zinc coating methods, while ASTM B487 and ASTM B499 offer methods for verifying coating thickness.