ASTM A754 Metallic Coatings on Steel by X-Ray Fluorescence

Scope:

ASTM A754 test method establishes a standard for calculating the weight and thickness of coatings on steel sheets by applying X-ray fluorescence or isotope measuring instruments. Zinc coating protects against corrosion. Different layer designations are formed as per the specifications of the zinc-coated steel sheet, which helps the purchaser choose the most suitable coating weight.

Test Procedure:

In ASTM A754, each instrument is operated such that the area of fluorescence remains between 970 and 3200 mm² for X-ray tube gauges and 3200 and 9000 mm² for isotope gauges. The traversing speed should be such that it leads to less than 1% test error, and the triple spot technique should be used to calculate coating weight. Stable temperature, accuracy, and cleanliness are to be practised.

Specimen Size : 

The specimen is created to the measurements specified.

Data:

For ASTM A754, weight is reported in SI units or Inch pound units.

Accuracy of X-ray tube and isotope coating weight gauges, when used for determining coating weight specifications are above 1.3 oz/ft²/side [400 g/m²/side] for zinc coatings, 0.066 oz/ft²/side [20g/m²/side] for tin coatings, and 0.82 oz/ft²/side [250 g/m²/side] for aluminium coatings.

Conclusion:

ASTM A754 test method establishes a standard for calculating the weight and thickness of coatings on steel sheets by applying X-ray fluorescence or isotope measuring instruments.