Corrosion behavior and tensile properties of AISI 316LN stainless steel exposed to flowing sodium at 823 K

• Published in: Journal of materials engineering and performance Vol. 9; no. 1; pp. 98 - 102
• Main Authors: RAJENDRAN PILLAL, S, SIVAI BARASI, N, KHATAK, H. S, TERRANCE, A. L. E, KALE, R. D, RAJAN, M, RAJAN, K. K
• Format: Journal Article
• Language: English
• Published: New York, NY Springer 01.02.2000; Springer Nature B.V
• Subjects: AGING; Applied sciences; Austenitic stainless steels; AUSTENITIC STEELS; Carburizing; Chromium; CORROSION; Corrosion tests; Elongation; Exact sciences and technology; HARDNESS; IMPURITIES; LEACHING; LIQUID METALS; MATERIALS SCIENCE; METALLOGRAPHY; Metals. Metallurgy; Nickel; Sample holders; SODIUM; TEMPERATURE RANGE 0400-1000 K; TENSILE PROPERTIES; Yield strength; Corrosion resistance; Austenitic stainless steel; Stainless steel-316; Sodium; Corrosion test; Tensile property; Steel; Experimental study; X ray diffraction; Molten metal corrosion; Tensile strength; Mass transfer
• ISSN: 1059-9495; 1544-1024
• DOI: 10.1361/105994900770346349

Austenitic stainless steel of the grade AISI 316 LN was exposed to flowing sodium in a loop at 823 K for 6,000 h to examine the corrosion and mass-transfer behavior. The specimens were incorporated in specially designed sample holders in the loop. These were retrieved and examined by various metallurgical techniques. Specimens were also subjected to thermal aging in the same sample holder to aid in separating the consequences of exposure to sodium from those cause by mere thermal effects. Microstructural investigations have revealed that thermal aging caused the precipitation of carbides at the grain boundaries. Exposure to sodium caused the leaching of elements such as chromium and nickel from the specimen. Loss of nickel from the austenite phase promoted the generation of ferrite phase. Microhardness investigation revealed the hardening of the sodium-exposed surface. Analysis using an electron Probe Microanalyzer revealed that the surface of the steel was both carburized and nitrided. Tensile tests indicated that there is no appreciable difference in the yield strength (YS) and ultimate tensile strength (UTS) of the thermally aged and sodium-exposed specimens when compared with the material in the as-received condition. However, the thermally aged and sodium-exposed specimens showed a decrease in the uniform elongation and total elongation at rupture, perhaps due to carburization and nitridation.