Science Research  Academic Press

Microstructural Optimization and Corrosion Resistance Enhancement of Austenitic 317L Stainless Steel through Tailored Heat Treatment

TianXiang  Zhao 
Jiayuan  Su 
Yuxin  Yang 
Kun  Cheng 
Kaicheng  Yu 
Keywords: Austenitic 317l stainless steel, Heat treatment, Microstructure, Electrochemical analysis, Passive current density, Metallographic structure, Corrosion resistance

Abstract

Austenitic 317L stainless steel was favored in many industrial applications due to its excellent corrosion resistance and mechanical properties. The study involved heat treating Austenitic 317L stainless steel samples at temperatures of 500℃, 950℃, and 1100℃ to explore the effects of heat treatment temperature on microstructure and corrosion resistance. Electrochemical analysis showed that the 317L sample treated at 1100℃ exhibited the lowest passive current density, indicating the best improvement in corrosion resistance at this temperature. Results from corrosion weight loss experiments confirmed that the least weight loss occurred under the heat treatment conditions of 950℃ and 1100℃, suggesting enhanced corrosion resistance of the material. Microstructural characterization revealed that after heat treatment at 950℃, the metallographic structure transformed from a complex, irregular size and chaotic growth pattern to uniformly grown and comparatively equal-sized metallographic structures. Furthermore, heat treatment at 1100℃ resulted in larger metallographic structures with reduced boundary width and distribution density. Consequently, enhanced corrosion resistance was observed at both temperatures. Based on these findings, a heat treatment range of 950℃ to 1150℃ appeared to be a suitable post-processing method for optimizing the microstructure of 317L while concurrently improving its corrosion resistance.