Previous work on the subject is reviewed, the fundamental properties of the alloy are described, and the results of the study of the isothermal aging processes of alloy containing 0.05 - 0.91 percentage by weight of chromium (Cr) are presented. A decrement of electrical resistivity during the aging process becomes more prominent as the chromium content increases up to 0.30 percent. The precipitation reaction after solution treatment at 950 deg C is most accelerated in 0.30 percent Cr alloy and is retarded in the alloys containing more chromium. The hardenability of the alloy due to aging is the maximum in 0.30 percent Cr alloy. It is concluded that quenched-in vacancies play an important part in the precipitation process of the alloy. The precipitation kinetics of the alloy are described. An anomolus change in electrical resistivity in the initial stage of isothermal aging was studied in greater detail, and the precipitation process of the alloy during step-annealing was investigated by electrical resistivity. The isothermal reversion of the alloy was also studied. Changes in mechanical properties during reversion are not so remarkable as those of electrical resistivity. Reversion behaviors may be explained by the critical size theory. Under suitable conditions, at least two kinds of reactions are observed separately: reversion of low temperature precipitate formed during step-annealing, and the formation of precipitate during pre-aging.

  • Corporate Authors:

    University of Tokyo

    Institute of Industrial Science, 7-3-1 Hongo, Bunkyo-ku
    Tokyo,   Japan 
  • Authors:
    • NAGATA, K
    • Nishikawa, S
  • Publication Date: 1975-3

Media Info

  • Features: Figures; References;
  • Pagination: p. 115-168

Subject/Index Terms

Filing Info

  • Accession Number: 00098652
  • Record Type: Publication
  • Report/Paper Numbers: Report-Vol. 24, #4
  • Files: TRIS
  • Created Date: Sep 10 1975 12:00AM