... of coupons did not receive this passivation treatment (only natural auto-passivation in atmosphere) for comparison purpose. The following test matrix was performed: Cleaned coupon passivated in nitric acid = test with a scan rate of 50mV/24h (forward and reverse scan) Cleaned coupon passivated in air...

... that are corrosive to carbon steel. For example, it was shown that sulfuric and nitric acid can be formed for certain undesirable impurity combinations and concentrations,1 see reactions 1 through 5. Elemental sulphur may also form in some situations (reaction 6).2 H2S + 3NO2 SO2 + H2O + 3NO 2NO + O2 2NO2 SO2...

... and crevice corrosion. Furthermore, the grade has very high mechanical strength with good microstructure stability and weldability. This paper presents new data from general corrosion testing of UNS S83071 in various acid and caustic environments, including formic acid, nitric acid, phosphoric acid, sodium...

... on a corroded aluminum surface. To address this issue, studies have been completed to evaluate a two-step method for corrosion analysis. First, ultrasonic cleaning of coupons in nitric acid more effectively removes corrosion from the corroded surface. Second, follow-on analysis of the cleaned coupons with both...

... Abstract Citric acid passivation offers a promising alternative to nitric acid passivation, particularly for free machining and precipitation hardened stainless steels where the latter requires the addition of sodium dichromate. While citric acid passivation is defined in industry...