Structure and mechanical properties of chrome-nickel-molybdenum steels with carbon content from 0,1 to 0,4 % after slow continuous cooling in the bainitic temperature range with cooling rate V cool = 5 °С/min were investigated. It was shown that at carbon content about 0,10-0,15 % after such heat treatment the structure of carbide-free-bainite represented as two-phase mixture of carbon depleted bainitic ferrite and carbon enriched retained austenite with different morphology were formed in steel. It was found that such carbide-free-bainite possesses significantly more high values of impact strength in comparison with bainite containing carbide precipitations having practically the identical level of hardness and strength. Retained austenite in such carbide-free-bainite is substantially enriched with carbon and contain the considerable part of steel total carbon content. The impact strength level increase is associated with the presence of significant quantity of carbon enriched retained austenite in carbide-free-bainite. It was assumed that for steels with bainitic structure formed under continuous cooling the carbon share content in retained austenite can characterize the morphological peculiarities of the phase transformation structural constituent (carbide-free-bainite ore bainite with carbides) and impact strength level of steel.

About the authors

A. Yu Kaletin

Institute of Metal Physics, Ural Branch of RAS

Yu. V Kaletina

Institute of Metal Physics, Ural Branch of RAS


  1. Bhadeshia H.K.D.H. Bainite in Steels. - 2nd edition. - London: The Institute of Materials, 2001. - 460 p.
  2. Bojarski Z., Bold T. Structure and properties of carbide-free-bainite / Acta Met. -1974. - Vol. 22, no. 10. - P. 1223-1234.
  3. Caballero F.G., Bhadeshia H.K.D.H. Very strong bainite // Current Opinion in Solid State and Materials Science: DK 8. - 2004. - P. 251-257.
  4. Калетин А.Ю. Влияние остаточного аустенита на структуру и свойства конструкционных сталей после высокого отпуска: дис. … канд. техн. наук. - Свердловск, 1985. - 199 с.
  5. Garcia-Mateo C., Caballero F.G., Bhadeshia H.K.D.H. Mechanical properties of low-temperature bainite // Materials Science Forum 500. - 2005. - P. 495-502.
  6. Калетин Ю.М., Рыжков А.Г., Калетин А.Ю. Влияние кремния и алюминия на свойства конструкционных хромоникелевых сталей с бейнитной структурой // Изв. вузов. Черная металлургия. - 1989. - № 6. - С. 96-99.
  7. Влияние стабильности остаточного аустенита на трещиностойкость конструкционной стали / М.Н. Георгиев, А.Ю. Калетин, Ю.Н. Симонов, В.М. Счастливцев // ФММ. - 1990. - № 1. - С. 113-121.
  8. Sandvik B.P.V. The bainite reaction in Fe-Si-C alloys: the primary stage // Met. Trans. - 1982. - Vol. 13A, no. 5. - P. 777-787.
  9. Microstructure-properties relationships in carbide-free bainitic steels / J.C. Hell, M. Dehmas, S. Allain, J.M. Prado // ISIJ international. 2011. - Vol. 51, no. 10. - P. 1724-1732.
  10. Охрупчивание конструкционной стали с бейнитной структурой при отпуске / А.Ю. Калетин, В.М. Счастливцев, Н.Т. Карева, М.А. Смирнов // ФММ. - 1983. - Т. 56, вып. 2. - С. 366-371.
  11. Структура и свойства конструкционных сталей после термомеханической обработки в бейнитной области температур / В.М. Счастливцев, Ю.В. Калетина, М.А. Смирнов, А.Ю. Калетин // Деформация и разрушение материалов. - 2011. - № 4. - С. 1-9.



Abstract - 29

PDF (Russian) - 18


  • There are currently no refbacks.

This website uses cookies

You consent to our cookies if you continue to use our website.

About Cookies