Work Item
ASTM WK88258
Revision of A123/A123M-17 Standard Specification for Zinc (Hot-Dip Galvanized) Coatings on Iron and Steel Products
Rationale
Under Paragraph 8.2.1, a new note 11 is proposed to explain the reason for a common inspection concern where variation in coating thickness measurements (both higher or lower) are observed for parts with different initial surface conditions prior to hot-dip galvanizing. Such variations should be considered during inspection to accurately represent the average coating thickness of specimens.
In the marketplace, it is common for the galvanizer to receive requests from the purchaser to limit coating thickness on reactive steels by reducing immersion times in the galvanizing kettle. As immersion time is only one of many variables that influence the final coating thickness, this practice is not known to guarantee the desired result. Additionally, the potential effectiveness of this strategy is further reduced when fabrications contain a mixture of reactive and non-reactive steels, or if the geometry, vent/drain holes, and orientation of the part do not allow for effective immersion and withdrawal from the galvanizing kettle. A new note 12 is proposed to alert the specifier of the possibility for insufficient coating thickness on non-reactive steel compositions when galvanizing fabrications containing a mixture of steel compositions within the same material category and thickness range. A reference to ASTM A385 is provided where additional background information is available.
Work Item Status
Date Initiated: 10-27-2023
Technical Contact: Alana Fossa