Study on corrosion damage of S13Cr martensitic stainless steel during the in-situ conversion process of shale oil

Under in-situ conversion process of shale oil characterized by ultra-high temperature, high pressure, and multiple corrosive media, the corrosion behavior and mechanical degradation of S13Cr martensitic stainless steel were systematically investigated. The results show that the corrosion rate of S13Cr in this environment reached as high as 1.81±0.04 mm/a. A bilayer coronal film with an intermediate phase was formed on the steel surface. The outer layer, composed of loose and porous Fe 3 O 4 together with island-like Fe 5 Ni 4 S 8 , exhibited weak adhesion to the substrate and was prone to large-area spallation. The inner layer consisted of FeCr 2 O 4 doped with FeS, whose structural integrity and protective capability were significantly reduced, ultimately leading to the simultaneous degradation of corrosion resistance and mechanical properties. These findings are of great significance for evaluating the service life of S13Cr under realistic in-situ conversion process and provide a fundamental basis for the selection and development of corrosion-resistant materials for such harsh environments.