Influence of Increasing Notch Radius on Properties of Nitrided Hot Work Tool Steels

  1. Prof. Dr. P. Neumann3,
  2. Dr. D. Allen4 and
  3. Prof. Dr. E. Teuckhoff5
  1. M. Rosso1,
  2. G. Scavino1,
  3. D. Ugues1 and
  4. A. Bennani2

Published Online: 5 JAN 2006

DOI: 10.1002/3527606181.ch20

Steels and Materials for Power Plants, Volume 7

Steels and Materials for Power Plants, Volume 7

How to Cite

Rosso, M., Scavino, G., Ugues, D. and Bennani, A. (2000) Influence of Increasing Notch Radius on Properties of Nitrided Hot Work Tool Steels, in Steels and Materials for Power Plants, Volume 7 (eds P. Neumann, D. Allen and E. Teuckhoff), Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim, FRG. doi: 10.1002/3527606181.ch20

Editor Information

  1. 3

    Max-Planck-Institut für Eisenforschung, Max-Planck-Str. 1, 40237 Düsseldorf, Germany

  2. 4

    ABB Asltom Power UK Ltd., Cambridge Road, Whetstone, Leicester LE9 GLH, United Kingdom

  3. 5

    Siemens AG, Postfach 3240, 91050 Erlangen, Germany

Author Information

  1. 1

    Politecnico di Torino, Dipartimento di Scienza dei Materiali e Ingegeneria Chimica, Italy

  2. 2

    COGNE Acciai Speciali, Aosta, Italy

Publication History

  1. Published Online: 5 JAN 2006
  2. Published Print: 27 JUN 2000

Book Series:

  1. EUROMAT 99

ISBN Information

Print ISBN: 9783527301959

Online ISBN: 9783527606184



  • steels for power plants;
  • materials for power plant;
  • increasing notch radius influence;
  • properties of nitrided hot work tool steels


Tool steels are a very large group of complex alloys which have evolved for many diverse hot and cold forming applications and they constitute a class of strategic materials. Hot work tool steels fall into groups which have either chromium, tungsten, or molibdenum as the major alloying element. The medium carbon and the relatively high alloy content make these steels air hardenable and resistant to impact and softening during repeated exposure to hot working operations.

In this work the impact properties of Charpy U-notch samples with increasing notch radius are presented and discussed. The samples were manufactured with AISI HI3 hot working tool steel and a modified composition, and were tested in the as quenched state and after nitriding. After the impact test, the microhardness properties were evaluated and correlated to the heat treatment. The notch radius strongly affect the impact resistance of the samples, namely at the lowest values. The microstructure details and the fracture morphology were observed by light microscopy and SEM.