Corrosion in Some Iron Alloys

This work contains many investigations to estimate the corrosion behavior of iron alloys such as (BC18, BC13, 25CrMo4) during exposure to inorganic acids (Hcl─HNO₃─H₂SO₄) and (NaOH). Chemical compositions of allays were analyzed by spectrometer type (ARL), in weight percent. Many heat treatments were done to show their effects on corrosion resistance. Investigated specimens in disc form were immersed in aggressive mentioned solutions, for defined times. The lost in weight of specimens due to corrosion were removed manually and registered. The corrosion rates (g/m²ċh) were calculated according the Eq. (2) referred to in the text, during exposure time of (120) h and (240) h for some alloys. This enables the conclusion that alloys with Cr% more than 12 % had more corrosion resistance than others. Also heat treatment improved corrosion resistance, and that solution of the acids was the most aggressive medium.