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Journal of Materials Science

, Volume 30, Issue 24, pp 6257–6266 | Cite as

Mechanical stability and magnetic properties of austenite

  • M. Ahmed
  • I. Nasim
  • H. Ayub
  • F. H. Hashmi
  • A. Q. Khan
Article

Abstract

Austenitic alloys have been produced by additional alloying in maraging steel grade 18 Ni at 2400 MPa. The concentration of Mo, Ni and Co was increased individually until the martensite start temperature Ms, was suppressed below ambient value. Charpy impact strength, tensile strength and magnetic properties were determined. The impact strength in the annealed condition ranged between 260 to 294 J. In alloys where martensitic transformation occurred following quenching in liquid nitrogen, the impact strength dropped appreciably and was found to be in the range 120–216 J. The tensile strengths of the austenite and martensite phases ranged between 680 to 890 and 1030 to 1100 MPa, respectively. It was observed that the austenite phase transformed to martensite in the region that under went plastic deformation during Charpy and tensile testing. The degree of transformation incorporated, varied as a function of composition. The magnetic properties of the austenite phases were typical of a very weak magnetic material. The coercive field and saturation magnetization values were in the range 1034–2387 Am−1 and 1.6–2.9 T, respectively. In contrast to the general observation, the austenite phase containing high Co exhibited ferromagnetic behaviour. The coercive field and saturation magnetization of ferromagnetic austenite was 1034 Am−1 and 11 T, respectively.

Keywords

Austenite Tensile Strength Martensite Magnetic Property Saturation Magnetization 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Chapman & Hall 1995

Authors and Affiliations

  • M. Ahmed
    • 1
  • I. Nasim
    • 1
  • H. Ayub
    • 1
  • F. H. Hashmi
    • 1
  • A. Q. Khan
    • 1
  1. 1.Dr A. O. Khan Research LaboratoriesKahutaPakistan

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