Corrosion and Deterioration Behavior of Iron Specimens in Qingdao Indoor Atmospheric Environment

One-year environmental monitoring was carried out in Qingdao indoor environment without temperature and humidity control, and white cast iron and gray cast iron were placed in this environment to investigate the corrosion of the two samples. The corrosion products on the surface of the samples were analyzed by ultra-depth-of-field microscopy, SEM-EDS and laser Raman spectroscopy, and the corrosion mechanism of indoor environmental factors on iron cultural relics in museums was discussed. The results showed that Fe₂O₃ was the main product in the initial corrosion stage of the two samples, and γ-FeOOH, α-FeOOH and a small amount of β-FeOOH were subsequently detected. With the prolongation of corrosion time, the content of Fe₂O₃ and γ-FeOOH increased first and then decreased, and the content of α-FeOOH increased. The corrosion degree of the sample was closely related to the indoor environmental factors. Under the same conditions, the corrosion degree of gray cast iron was less than that of white cast iron.