PASSIVATION OF STAINLESS STEEL AND SPECIAL MATERIALS
At Raff + Grund the components can be passivated with nitric acid. In addition to the automatic formation of a passive layer after pickling, a separate passivation tank is available with dimensions: 1.5 x 1.5 x 1.2m high. The passivation with nitric acid produces a significantly thicker passivation layer than is achieved by passivating in air. In this way, materials that cannot be pickled and polished stainless steel components can be passivated. By passivating with nitric acid, polished surfaces do not become matt, as is the case during the pickling process. However, the components must be completely free of temper colours and ferritic contaminations.
It is also possible to passivate to ASME-BPE. This involves using citric acid as the passivator.