A STUDY ON LOW-TEMPERATURE NOTCH TOUGHNESS OF 9% NI STEEL

In quenching and tempering heat treatment of 9% Ni steel, one of the most important factors affecting the notch toughness at low temperatures is the tempering temperature, fundamentally based on the true Ac sub 1 transformation temperature. Another is the cooling rate dependence after tempering: the faster the cooling rate becomes, the higher the notch toughness is. From the above factors, this investigation has experimentally clarified the following phenomena: 1. A tempering temperature lower than the true Ac sub 1 transformation temperature provides high notch toughness. This effect is considered to be due to the formation of stable ferrite in the matrix. It is concluded that the austenite precipitating at a tempering temperature does not contribute to the notch toughness. 2. Even when the notch toughness is lowered by a slow cooling rate, it can easily be regained by a rapid cooling rate after the subsequent tempering heat treatment. This effect is considered to be related to carbide behavior in the matrix.

• Corporate Authors:

  Japan Association for Technical Information

  4-7-107, Yamazaki-cho, Machida City
  Tokyo 194-01,   Japan 
• Authors:
  • Saiga, Y
  • Fukagawa, M
  • Ito, S
• Publication Date: 1973

Media Info

• Features: References;
• Pagination: p. 35-47
• Serial:
  • Japan Shipbuilding and Marine Engineering
  • Volume: 7
  • Issue Number: 3
  • Publisher: Japan Association for Technical Information

Subject/Index Terms

• TRT Terms: Low temperature materials; Metal heating; Nickel alloys; Notching (Cutting); Strength of materials
• Uncontrolled Terms: Heat treatment
• Old TRIS Terms: Notch toughness
• Subject Areas: Marine Transportation; Materials;

Filing Info

• Accession Number: 00054394
• Record Type: Publication
• Source Agency: Department of Transportation
• Files: TRIS, USDOT
• Created Date: Jun 18 1974 12:00AM