Imaging of morphological and physicochemical changes occuring in the structure of austenitic steel due to the thermal sensitization

In polycrystalline materials, grain boundaries are always where phenomena such as surface diffusion, sedimentation and corrosion occur. They have a significant impact on the macroscopic properties of the construction material [1]. In addition to inhomogeneities such as manganese sulphide inclusions formed during the metallurgical process, interfacial formation of intermetallic phases can also be observed in austenitic steel as a result of thermal sensitization. Depending on the conditions of the phenomena occurring in the steel structure, carbides, nitrides, Laves phases or other compounds may be formed. The set contains the results of monitoring the surface of high-alloy AISI 304 steel, previously subjected to intentional sensitization. Differences in electrical conductivity were found, proving the existence of various chemical species on the surface, which affects the deterioration of the material resistance in the event of its exposure to the corrosive environment. Measurements were performed in contact mode using CDT-NCHR conductive probes. The collection contains 18 images and 4 polarization curves.
[1]       R. Singh, I. Chattoraj, A. Kumar, The effects of cold working on sensitization and intergranular corrosion behavior of AISI 304 stainless steel, Mater. Trans. A. 34 (2003) 2441–2447. http://link.springer.com/article/10.1007/s11661-003-0004-5 (accessed June 6, 2013).