(a) Released amount of Fe during nitric acid passivation from abraded AISI 304 (2 h, 6 M HNO₃, 60°C) and during subsequent exposure to 5 g/L citric acid (pH 2.4) at 40°C for 24 h;¹⁴ (b) corresponding relative content of metals in the surface oxide;¹⁴ released amounts of metals (c) Fe, (d) Cr, (e) Ni, and (f) Mn from stainless steel grade 304 in different solutions: (i) 0.5 M NaCl (pH 2.2 and 5.5; denoted NaCl), (ii) 5 g/L citric acid (pH 2.4; denoted CA), and (iii) 0.5 M NaCl + 5 g/L citric acid (pH 2.2 and 5.5; denoted NaCl + CA) for 2 h at 70°C followed by 24 h at 40°C. This is shown for coupons that were not pre-passivated, and coupons that were first passivated in 5 g/L citric acid for 2 h at 70°C, all as-received (surface finish 2B). The Ni release of the pre-passivated coupons (e) was close to the detection limits. The error bars show the standard deviation of triplicate samples and in the case of Cr release in NaCl-containing solutions also the overestimation error (<30%) during analysis.