Significance and Use
These test methods for the chemical analysis of zinc-nickel alloy coating on sheet steel are primarily intended as referee methods to test such materials for compliance with compositional specifications such as found in Specification A918, particularly those under the jurisdiction of ASTM Committee A05 on Metallic-Coated Iron and Steel Products. It is assumed that all who use these test methods will be trained analysts capable of performing common laboratory procedures skillfully and safely. It is expected that work will be performed in a properly equipped laboratory under appropriate quality control practices such as those described in Guide E882.
These test methods must be applied twice, once to each side of the specimen if coating mass and composition are required for both sides of a coated sheet. Two separate specimens are required for this purpose.
Scope
1.1 These test methods cover independently the chemical analysis of each surface of zinc-nickel alloy electrolytically coated on steel sheet. The coatings have chemical compositions within the following limits:
Analyte Concentration Range
Coating mass 0.0 to 80 g/m2
Nickel 7.0 to 17.0 %
1.2 These test methods are in the following sections:
Sections
Coating mass, by the Weigh-Strip-Weigh Method
(20.0 to 45.0 g/m2) 10-20
Nickel by the Atomic Absorption Method (11.0 to 13.5 %
of Coating mass Ranging from 20 to 45 g/m2) 21-31
1.3 The values stated in SI units are to be regarded as standard. In some cases, exceptions allowed in Practice are also used.
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.