In the current work the surface of stainless steel 1Cr18Ni10Ti irradiated by 5,7 MeV protons in iodine medium was studied by standard Rutherford backscattering and X-ray photoelectron spectroscopy. Possible chemical processes and compounds containing iodine, oxygen and steel components were determined. Proton irradiation induces humid air radiolysis products. The air radiolysis products are intensively involved in iodine transport.