ASTM A143 Responsibilities

ASTM A143 provides procedures to safeguard against embrittlement in galvanized steel. But who’s responsible for what?

ASTM A143/A143M establishes practices to reduce the risk of embrittlement and outlines methods for identifying its occurrence. The standard focuses on the conditions under which embrittlement may develop and assigns responsibilities across the design, fabrication, and galvanizing process. This article offers a practical industry interpretation of those responsibilities and highlights project-specific points that may require additional discussion.

Ultimately communication between the designer, fabricator, and galvanizer is key. Communication throughout the design, fabrication, and galvanizing processes ensures best practices are used throughout and thus minimize the possibility of embrittlement.

Different forms of Embrittlement

Understanding the types of embrittlement that may occur during galvanizing and how each can be prevented helps clarify stakeholder responsibilities. Hydrogen embrittlement is one of the most widely known types of embrittlement, but is highly unlikely in conventional structural steels. In practice, strain-age embrittlement is more commonly encountered in hot-dip galvanizing than other forms of embrittlement.

Different forms of embrittlement are often confused, although the mechanisms and timing differ:

• Hydrogen embrittlement: Caused by hydrogen trapped within steels that have tensile strengths above 150 ksi (1,100 MPa); cracking typically occurs later under service load
• Strain-age embrittlement: Caused by prior cold work and residual stresses; cracking is often observed shortly after galvanizing
• Liquid Metal Assisted Cracking: Caused by a rare combination of steel characteristics, residual stresses, and galvanizing processing variables; cracking is often observed shortly after galvanizing

For more information, AGA publishes additional guidance on Types of Embrittlement & HDG, and the methods to avoid Hydrogen Embrittlement, and Strain-Age Embrittlement, Cracking due to High Residual Stress, and Corner Cracking of Square and Rectangular HSS.

Responsibilities for Preventing Embrittlement

ASTM A143 emphasizes that prevention of embrittlement is a shared responsibility among the designer, fabricator, and the galvanizer, with primary control occurring before galvanizing.

Designer / Specifier

The designer or specifier has primary responsibility to:

• Select steels suitable for hot-dip galvanizing
• Identify high-strength components (>150 ksi / 1,100 MPa)
• Avoid designs with severe cold work, small bend radii, sharp bends, notches, or stress concentrators
• Communicate any susceptibility concerns to the fabricator and galvanizer

Proper material selection and design detailing are the most effective means of preventing embrittlement.

Fabricator

The fabricator is responsible for controlling fabrication-induced risks:

• Avoid excessive cold deformation, punching, or bending that introduces high residual stress prior to galvanizing
• Address the finishing of holes and thermal-cut edges positioned near areas of high residual stress
• Use recommended bend radii and fabrication practices described in A143, at least 3 times the section thickness or as large as practical
• Identify and communicate areas of high hardness or cold work
• Notify the galvanizer when susceptible materials are present; this can be achieved by providing Material Test Reports (MTRs)

Fabrication practices play a critical role because cold work and localized hardening are key drivers of embrittlement risk.

Galvanizer

The galvanizer’s role is to apply appropriate processing controls based on the information provided:

• Maintain proper surface preparation and pickling parameters
• Adjust cleaning methods when high-strength steels are identified
• Use alternative methods such as blasting and controlled (“flash”) pickling where appropriate
• Limit pickling exposure to reduce hydrogen generation

The galvanizer’s responsibility is conditional on receiving accurate information about the material being processed.

Practical Industry Interpretation

For steels galvanized in accordance with ASTM A123, embrittlement is not typically considered an inherent risk of the galvanizing process.

Several factors support this conclusion:

• Most steels galvanized fall below the strength threshold associated with embrittlement
• Heating during galvanizing promotes the release of absorbed hydrogen
• Susceptibility is primarily governed by steel strength, microstructure, and prior fabrication history

As a result, responsibility for mitigating risk lies primarily with the designer and fabricator, who must identify susceptible materials and fabrication conditions. The galvanizer applies appropriate mitigations once this information is provided.

ASTM A143 provides clear guidance to mitigate risk of embrittlement through:

• Appropriate material selection
• Controlled fabrication practices
• Effective communication between project stakeholders

When these practices are followed, embrittlement remains a rare and manageable concern.

For the vast majority of structural steel applications galvanized to ASTM A123, performance is unaffected, and the benefits of galvanizing—durability, longevity, and corrosion protection—are realized without increased risk of embrittlement.