Title

LOADING AND TEMPERATURE DEPENDANT FATIGUE PARAMETERS OF WORKING ROLL SURFACE LAYER MATERIAL

LOADING AND TEMPERATURE DEPENDANT FATIGUE PARAMETERS OF WORKING ROLL SURFACE LAYER MATERIAL

Authorship

Drobne, Matej; Glodež, Srečko

Drobne, Matej

I am this author

Glodež, Srečko

I am this author

DOI

10.5151/2594-5297-24144

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Abstract

This paper deals with loading and temperature dependant fatigue parameters of working roll surface layer material. The research is performed on working rolls, where High Chromium Steel (HCrS) is used for roll’s shell material. Before fatigue testing, monotonic mechanical properties (ultimate compressive and ultimate tensile strength) are determined at different temperatures, using standardized testing procedures. Fatigue testing is performed on a servo – hydraulic testing machine with consideration of different loading ratios (R = 0, R = -1) and different initial temperatures of the specimens (20 °C, 600 °C). On the basis of the experimental results the S – N curves are constructed, from which typical fatigue parameters (the fatigue strength coefficient σf’ and the fatigue strength exponent b) are determined. After fatigue testing a comprehensive research of fracture surfaces is performed using the Scanning Electron Microscope (SEM). Thereafter, the line profile Energy Dispersive X–ray Spectroscopy (EDS) is performed to determine content elements and carbides inside crystal grains and around grain boundaries. Experimental results presented in this paper will serve as a basis for further research related to fatigue behaviour of working rolls in hot strip mills made of HCrS.

This paper deals with loading and temperature dependant fatigue parameters of working roll surface layer material. The research is performed on working rolls, where High Chromium Steel (HCrS) is used for roll’s shell material. Before fatigue testing, monotonic mechanical properties (ultimate compressive and ultimate tensile strength) are determined at different temperatures, using standardized testing procedures. Fatigue testing is performed on a servo – hydraulic testing machine with consideration of different loading ratios (R = 0, R = -1) and different initial temperatures of the specimens (20 °C, 600 °C). On the basis of the experimental results the S – N curves are constructed, from which typical fatigue parameters (the fatigue strength coefficient σf’ and the fatigue strength exponent b) are determined. After fatigue testing a comprehensive research of fracture surfaces is performed using the Scanning Electron Microscope (SEM). Thereafter, the line profile Energy Dispersive X–ray Spectroscopy (EDS) is performed to determine content elements and carbides inside crystal grains and around grain boundaries. Experimental results presented in this paper will serve as a basis for further research related to fatigue behaviour of working rolls in hot strip mills made of HCrS.

Keywords

Experiments; High cycle fatigue; High chromium steel.

Experiments; High cycle fatigue; High chromium steel.