Responsive carry out Ferroxyl testing in accordance with ASTM A380 and ASTM A967.
This test is a highly sensitive test and should be performed when no traces of free iron or iron oxide is acceptable on the Passivated items. The test can be used on stainless steel to detect iron contamination, including iron-tool marks, residual-iron salts from pickling solutions, iron dust, iron deposits in welds, embedded iron or iron oxide, etc.
Due to the use of Potassium Ferricynide this test method cannot be employed in the food industry.
Its all very well carrying out pickling and passivation of a stainless welds but how do you know if the passive layer has grown back to allow suitable corrosion resistance.
Responsive can prove the passive layer is present by carrying out passivity testing using the Passi-test plus range of products.