Proceeding of ABRASION2008

Abrasion Wear Resistant Alloyed Cast Irons For Rolling and Pulverizing Mills

Editor: M. Pellizzari. University of Trento, Italy, August 24-27, 2008

Wear and friction behaviour of High Chromium Iron and High Speed Steels for hot rolls

M. Pellizzari1, A. Molinari1, D. Cescato1, A. Tremea2, G. Corbo2, A. Biggi2

1University of Trento, Dpt. Materials Engineering and Industrial Technologies, Italy

2INNSE Cilindri, Brescia, Italy

Abstract

Tribological properties of spincast roll materials depends on the mechanical properties of the metallic matrix, on the carbides type, amount and morphology and on the ability of the material to develop a thin and adherent oxide layer which protects the surface from metallic and abrasive wear. All these characteristics depend on the chemical composition, which determines the solidification sequence and the residual content of alloying elements in the metallic matrix after heat treatment. By means of specific laboratory tests, aimed at simulating the phenomena which are responsible for the damage of the rolls, the friction and wear behaviour of some High Chromium Iron and High Speed Steels have been studied.

Keywords: HiCrIron, High Speed Steel…

Introduction

Roll materials produced by spincasting have a peculiar microstructure, comprising a tempered martensite matrix surrounded by an almost continuous network of eutectic carbides. Proeutectic carbides are also present in materials containing the proper combination of C, V and Nb [1]. Carbides increase the load bearing capacity of the material, and in turn the wear resistance. However, the combination of a high carbide amount and an inadequate matrix hardness may depress wear resistance, because of the occurrence of local plastic strain (at the carbide-matrix interface) which may cause delamination. Therefore, the high temperature mechanical properties of the metallic

Tables:

Tab.1. Heading of the table (TNR 10p size, normal style)

text / A / B / C / D
X / 0.25 / 1.29 / 2.32 / 3.96
Y / 5 / 13 / 27 / 39

(text and numbers in table TNR 10p. size)

Equations:

(1)

Fig.1. Heading of the figure
(TNR 10 p. size, normal style)

References

[1]Molinari, A., Tremea A., Pellizzari M., Biggi A., Corbo G.High speed steels for hot rolls with improved impact and thermal fatigue resistance. Materials Science and Technology, v.18, n.4, 2002, p. 1574-1580.

[2]Molinari, A., Pellizzari M., Biggi A., Corbo G., Tremea A.Primary carbides in spincast HSS for Hot Rolls and their effect on the Oxidation Behaviour. In: Proceedings of the 6th International Tooling Conference-Tool Steels: use and research, 10-13 September 2002, Karlstadt (Sweden), ed. J. Bergstrom et. al., p.365-377.

[3]Authors: title of monograph, publisher (year)