Precipitation of copper particles during pearlite transformation

Masahiro Murakami, Youhei Takanaga, Nobuo Nakada, Toshihiro Tuchiyama, Setsuo Takaki

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

It is known that e-Cu phase precipitates within fcrrite phase independently on ccmcntitc phase in steel. Therefore, Cu addition should be effective for strengthening carbon steels. In this study, Cu was added to Fc-0.8%C eutcctoid alloy up to 2mass% in order to obtain high strength pcarlitic steel. The effect of Cu on pearlitic transformation behavior and the detail of pcarlitic structure were also investigated. First of all, isothermal heat treatment was performed after austenitizing in the Cu bearing eutectoid steels to form pearlitic structure. Microstructural observations revealed that the pcarlitic transformation is significantly retarded by the addition of Cu, while the morphology of pearlite, such as lamellar spacing and block size, arc hardly influenced by the Cu addition. As a result of chemical analysis for the ccmcntitc phase, it was found that the short range redistribution of Cu atoms had been occurred from ccmcntitc to fcrrite through the intcrfacial diffusion at (pearlite / austcnitc) interface during the pcarlitic transformation. The Cu precipitated at the (fcrrite / austcnite) interfaces during pcarlitic transformation as well as within the ferrite phase after the transformation. This resulted in the age hardening during isothermal heat treatment in the eutectoid steel containing 2mass% Cu. The yield strength and tensile strength of the pearlite of Cu bearing eutectoid steels depended on not only lamellar spacing but also the dispersion of Cu particles precipitated in the ferrite phase. The 0.2% proof stress was given by the addition of precipitation strengthening in fcrrite phase to the strength of Cu-free pearlite. For example, the 2mass% Cu addition increases the 0.2% proof stress of pearlitic steel by approximately 250MPa at a maximum.

Original languageEnglish
Title of host publicationProceedings of the 17th IFHTSE Congress
PublisherThe Japan Society for Heat Treatment (JSHT)
Pages588-591
Number of pages4
Volume2
ISBN (Electronic)9780000000002
Publication statusPublished - Jan 1 2008
Event17th International Federation for Heat Treatment and Surface Engineering Congress 2008, IFHTSE 2008 - Kobe, Japan
Duration: Oct 26 2008Oct 28 2008

Other

Other17th International Federation for Heat Treatment and Surface Engineering Congress 2008, IFHTSE 2008
CountryJapan
CityKobe
Period10/26/0810/28/08

All Science Journal Classification (ASJC) codes

  • Surfaces, Coatings and Films
  • Condensed Matter Physics
  • Mechanics of Materials

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  • Cite this

    Murakami, M., Takanaga, Y., Nakada, N., Tuchiyama, T., & Takaki, S. (2008). Precipitation of copper particles during pearlite transformation. In Proceedings of the 17th IFHTSE Congress (Vol. 2, pp. 588-591). The Japan Society for Heat Treatment (JSHT).