Understanding the Corrosion Properties of Additively Manufactured and Conventional Stainless Steels
Additional Funding Sources
The project described is supported by the Micron School of Materials Science and Engineering and the American Chemical Society Project SEED Program.
Presentation Date
7-2019
Abstract
Found in homes, industries, and numerous other applications, stainless steel is favored for its resistance to corrosion and stains. A common grade of stainless steel is 316L, which is comprised mainly of iron with chromium (18%), nickel (14%), and molybdenum (3%) alloying additions. The high concentration of chromium within the alloy spontaneously forms a thin, passive chromium oxide on the surface of the steel, making it highly corrosion resistant. However, different production techniques can influence the microstructure and corrosion resistance of the alloy. While conventional manufacturing melts raw materials together, additive manufacturing (AM) techniques fuse layers of metallic powders to form the material. In this study, the metal microstructures of conventional and AM stainless steels were investigated with optical and electron microscopy. Electrochemical polarization tests were conducted on conventional and AM stainless steels in a sodium chloride solution to accelerate the corrosion process and obtain quantitative corrosion rate data. AM stainless steels had a lower corrosion rate than conventional stainless steels. In addition, the results showed that AM stainless steels were less susceptible to localized corrosion than conventionally processed steels. These findings suggest that advanced manufacturing can produce higher performing materials compared to conventional processing.
Understanding the Corrosion Properties of Additively Manufactured and Conventional Stainless Steels
Found in homes, industries, and numerous other applications, stainless steel is favored for its resistance to corrosion and stains. A common grade of stainless steel is 316L, which is comprised mainly of iron with chromium (18%), nickel (14%), and molybdenum (3%) alloying additions. The high concentration of chromium within the alloy spontaneously forms a thin, passive chromium oxide on the surface of the steel, making it highly corrosion resistant. However, different production techniques can influence the microstructure and corrosion resistance of the alloy. While conventional manufacturing melts raw materials together, additive manufacturing (AM) techniques fuse layers of metallic powders to form the material. In this study, the metal microstructures of conventional and AM stainless steels were investigated with optical and electron microscopy. Electrochemical polarization tests were conducted on conventional and AM stainless steels in a sodium chloride solution to accelerate the corrosion process and obtain quantitative corrosion rate data. AM stainless steels had a lower corrosion rate than conventional stainless steels. In addition, the results showed that AM stainless steels were less susceptible to localized corrosion than conventionally processed steels. These findings suggest that advanced manufacturing can produce higher performing materials compared to conventional processing.
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