Pickling and passivating gel
Pickling-passivating gel is a spreadable chemical mixture that simultaneously promotes descaling and formation of the passive protective layer on welds. It prevents pitting through defined exposure times.
Physicochemical Mechanism of Action
Pickling-passivating gel contains chemical additives that include both descaling agents and passivating agents. These substances react to the metal and form a thin protective layer that prevents contact with air and moisture. The descaling agents ensure that the metal remains clean and corrosion does not occur.
Metallurgical Relevance & Welding Risks
Using pickling-passivating gel reduces susceptibility to pitting and improves weld service life. If the gel is not applied correctly or is left on too long, it can lead to an excessively thick protective layer, which may impair mechanical strength. Also, if the gel is not left on long enough, it may not fully passivate and allow pitting.
Workshop Practice & Action Guidelines
Use pickling-passivating gel according to manufacturer instructions. Apply it to the weld within 30 minutes after grinding and allow it to act for at least 15 minutes before washing off and drying. Be careful not to leave the gel on for too long to avoid a too-dense protective layer.