Die Kinetik des Rostens von Eisen in der Atmosphäre

Abstract

Bei Laborversuchen zur Klärung der Kinetik der aktiven Perioden des atmosphärischen Rostens wurde festgestellt: Bei Temperaturen <O°C verläuft die Korrosion unabhängig von SO2‐Gehalt und der Feuchtigkeit der Atmosphäre. Über 0°C sind die Reaktionen geschwindigkeitsbestimmend, die zu Sulfatnestern und zur hydrolytischen Rostbildung führen. Bei gleichzeitiger Einwirkung höherer Temperaturen (≥15°C) und Oberflächenwassermengen(≥100 g.m−2) sinkt der beschleunigende Einfluß steigender SO2‐ Werte. Die gefundenen Korrosionsgeschwindigkeiten stimmen mit aus langzeitigen Naturversuchen berechneten gut überein.

A new understanding of the failure of waterborne acrylic coatings

“…(2) Oxygen, which diffuses through the intact coating near the defect, is reduced to OH À by the electron that is produced by the corrosion of the bare metal. 34 Therefore, the pH near the defect increases and a cathode is formed. Simultaneously, the defect becomes the anode.…”

Colour‐based assessment of atmospheric corrosion products, namely of flash rust, on steel

“…Also, atmospheric corrosion is usually a discontinuous process, characterized by an alternation of active corrosion periods (periods with electrolyte) and periods without corrosion (periods without electrolyte). The amount of corrosion products formed due to atmospheric corrosion can be described with the following equation 3: …”

“…Typical K ‐values for flash rust formation will be provided in the second part of this section. The corrosion, or reaction, velocity depends on various process parameters, namely on degree of salt coverage, coverage of the surface with water and on air temperature in the vicinity of the steel surface 3. Equation (1) defines the essential parameters that affect the formation of flash rust.…”

Atmospheric corrosion of reference metals in Antarctic sites

“…However, as noted by Barton et al (1974), in highly polluted atmospheres corrosion can continue to take place even at -5 ºC, due to the high saline concentration in the electrolyte film retained on the metal surface, which delays freezing (Brass, 1999, p. 29). In laboratory studies applying electrochemical techniques, different researchers have demonstrated that electrochemical corrosion activity is possible below ice layers (González, 1989, p. 297;Rosales et al, 1996, p.6).…”