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Ferrite Removal Control

The metrological monitoring of the selective removal of the austenitic matrix versus the ferrite content during the pickling process of duplex steels. This ensures the required phase ratio in the near-surface zone.

When pickling duplex steel, you have to be careful not to selectively dissolve the ferrite and leave the austenite behind. This happens when the pickling solution or temperature doesn't match the material. Once the phase ratio is off, the corrosion resistance and toughness of the weld suffer. So set the pickle according to the heat number and, if in doubt, check the result with a ferrite meter. If the value is off, the only fix is to grind the affected area and re-pickle.

MetallurgieSchweißtechnik

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