J. Mater. Sci. Technol. ›› 2021, Vol. 61: 234-246.DOI: 10.1016/j.jmst.2020.05.031

• Research Article • Previous Articles    

Influence of cementite spheroidization on relieving the micro-galvanic effect of ferrite-pearlite steel in acidic chloride environment

Hu Liua,c, Jie Weia,b,*(), Junhua Donga,b,*(), Yiqing Chenb, Yumin Wub, Yangtao Zhoua, Subedi Dhruba Babua,c, Wei Kea   

  1. aShenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China
    bState Key Laboratory of Metal Material for Marine Equipment and Application, Anshan, 114009, China
    cSchool of Materials Science and Engineering, University of Science and Technology of China, Hefei 230026, China
  • Received:2020-02-21 Revised:2020-05-12 Accepted:2020-05-21 Published:2021-01-20 Online:2021-01-20
  • Contact: Jie Wei,Junhua Dong

Abstract:

The corrosion behavior of the as-received steel and the spheroidized steel in acidic chloride environment was investigated. The results indicate the corrosion mode and corrosion rate of two steels are diverse due to their difference in microstructure. For as-received steel with ferrite-pearlite microstructure, severe localized corrosion happens on the pearlite regions, and plenty of cathodic cementite remains in the pits, further strengthening the micro-galvanic effect and accelerating the corrosion rate. While for spheroidized steel with tempered martensite microstructure, the nanosized cementite particles evenly distributed on the ferrite substrate are easy to fall off, which can significantly reduce the cementite accumulation on the steel surface, relieving the acceleration effect of micro-galvanic corrosion.

Key words: Ferrite-pearlite steel, Acidic chloride environment, Granular cementite, Micro-galvanic corrosion