GB/T 31931-2015 《Zinc or zinc alloy coating on steel sheets or strips—Determination of hexavalent chromium content—1,5-Diphenylcarbohydrazide (diphenylcarbazide) spectrophotometric method》 Related products

This standard specifies a method for the determination of hexavalent chromium content in zinc and zinc alloy platings on the surface of steel plates and steel strips using the Spectrophotometric method, spectrophotometry. It is suitable for the determination of hexavalent chromium content in pure zinc plating, zinc-iron alloys, zinc-aluminum and aluminum-zinc alloys, and the determination range is 2 μg/g to 100 μg/g or 0.020 μg/cm ² to 10 μg/cm ². The method uses a spectrophotometer to determine the hexavalent chromium content at a wavelength of 540 nm by leaching hexavalent chromium in platings. It is suitable for environmental protection and mass testing of steel products.