CSA Group Nickel alloys - Determination of chromium content - Potentiometric titration method with ammonium iron(II) sulfate ISO 7529:2017

ISO 7529:2017 specifies a potentiometric titration method for the determination of chromium content in nickel alloys which do not contain insoluble carbides and which have a vanadium content less than a mass fraction of 0,2 %. The method is applicable to chromium contents between a mass fraction of 5 % and a mass fraction of 22 %. Vanadium, which can be present as an impurity in the alloy, will give a positive bias interference. However, at a level of a mass fraction of 0,2 %, this bias is equivalent to a mass fraction of 0,068 % chromium, which is about half the reproducibility of the method.