Resistance of welded joints 304 and 304H to intercrystalline corrosion

Abstract

Austenitic steels belong to the group of materials with high application potential in the power industry. Due to the high working temperature and corrosive environment, it is necessary to determine the resistance to intercrystalline corrosion of austenitic steels. The paper presents the results of intergranular corrosion resistance test of TIG welded joints made of 304 and 304H steels. The studies were carried out in a solution of 40% sulfuric acid (VI) and iron (III) sulfate, and then the samples were bent in accordance to the requirements of PN-EN ISO 3651-2. The study has demonstrated that steels with austenitic structure are characterized by good resistance to intergranular corrosion, which was additionally confirmed by structural studies high magnification and microanalysis of chemical composition of EDS. Basing on the obtained results the structure of steel welded joints of 304 and 304H steels after the intergranular corrosion resistance test has been described.

Keywords

• steel 304
• steel 304H
• intergranular corrosion
• TIG welding