Patterns and Mechanisms of Pitting of Heat Exchangers Made of AISI 321 and 08Kh18N10T Steels During their Operation in Recycled Water
Snizhnoi G. Pulina T. Solidor N. Yar-Mukhamedova G. Imanbayeva A. Zellele D. Mussabek G.
26 December 2025Institute of Combustion Problems, al-Farabi Kazakh State National University
Eurasian Chemico-Technological Journal
2025#27Issue 4305 - 313 pp.
The article examines the patterns and mechanisms of pitting corrosion in AISI 321 and 08Kh18N10T stainless steels under conditions simulating recycled waters used in heat exchanger operation. It was established that the critical pitting temperature (CPT) of these steels increases significantly with increasing pH and decreasing chloride concentration in model solutions. The influence of the structural components of the steels was found to be less significant than that of the chloride-containing environment and to depend strongly on its parameters (pH and chloride concentration). In acidic model recycled waters (pH 4), AISI 304 steels – which contains minimal amounts of titanium nitrides, aluminum oxides, and carbon – exhibits the highest CPT values, regardless of the chloride concentration in the range of 350–600 mg/L. In contrast, AISI 321 and 08Kh18N10T steels, characterized by the highest volume fractions of titanium nitrides, as well as melt 2 of AISI 321 steel and 12Kh18N10T steel with elevated carbon content, show the lowest CPT values. Based on an analysis of the literature, it is hypothesized that this behavior may be attributed to the increased overvoltage of hydrogen ionization on titanium nitrides and carbonitrides, which act as initiation sites for pit formation and propagation. Additionally, the corrosion rate was found to correlate with the specific paramagnetic susceptibility χ0 of austenite, a parameter reflecting the atomic magnetic state and determined by the chemical composition and phase structure of the alloy.
AISI 321 and 08Kh18N10Т steels , Chloride-containing medium , Heat exchanger , Pitting resistance , Specific paramagnetic susceptibility
Text of the article Перейти на текст статьи
National University Zaporizhzhia Polytechnic, 64 Zhukovsky Str., Zaporizhzhya, UA-69063, Ukraine
Al-Farabi Kazakh National University, 050040, Al-Farabi ave., 71, Almaty, Kazakhstan
National University Zaporizhzhia Polytechnic
Al-Farabi Kazakh National University
10 лет помогаем публиковать статьи Международный издатель
Книга Публикация научной статьи Волощук 2026 Book Publication of a scientific article 2026