Pitting Corrosion Resistance of Martensite of AISI 1045 Steel and the Beneficial Role of Interstitial Carbon

• Published in: Journal of the Electrochemical Society Vol. 164; no. 14; pp. C962 - C972
• Main Authors: Kadowaki, Mariko, Muto, Izumi, Sugawara, Yu, Doi, Takashi, Kawano, Kaori, Hara, Nobuyoshi
• Format: Journal Article
• Language: English
• Published: The Electrochemical Society 01.01.2017
• ISSN: 0013-4651; 1945-7111
• DOI: 10.1149/2.0541714jes

The pitting corrosion resistance of AISI 1045 carbon steel with as-quenched, tempered, and low-carbon martensitic microstructures was investigated in boric-borate buffer solutions with and without NaCl. Analysis by micro-scale polarization found that tempering and decarburizing treatments decreased the pitting corrosion resistance of as-quenched martensite. The high corrosion resistance of the as-quenched martensite was likely due to the large amount of interstitial carbon. The pitting corrosion resistances of as-quenched martensite, primary ferrite, and pearlite were compared using micro-scale polarization measurements. It was determined that the pitting corrosion resistances of the typical steel structures were ordered as follows: (high) as-quenched martensite > tempered martensite ≈ primary ferrite > pearlite (low). The pitting corrosion resistance of steel was shown to depend on its microstructure.