Title

MULTI-SCALE FINITE ELEMENT MODELING AND MICROSTRUCTURAL OPTIMIZATION OF CAST HIGH SPEED STEEL FINISHING ROLLS

MULTI-SCALE FINITE ELEMENT MODELING AND MICROSTRUCTURAL OPTIMIZATION OF CAST HIGH SPEED STEEL FINISHING ROLLS

Authorship

Redkin, Konstantin V.; Vipperman, Jeffrey S.; Hrizo, Christopher; Schleiden, Raymond; Garcia, Calixto I.

DOI

10.5151/2594-5297-24149

Downloads

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Abstract

A detailed microstructural evaluation was conducted on a series of radial samples from the shell of high speed steel (HSS) work rolls produced by centrifugal spin casting. Continuous local transformations were simulated using FEM and thermodynamic predictions. Microstructural observations from production rolls validated non-linear heat transient results and actual thermo-processing data. FEM sub-structuring and image processing techniques were implemented to aid in the development of a multi-scale model to simulate the local response of an individual microstructural constituents, i.e. carbides and/or matrix, under heat treatment (HT) conditions. The proper as-cast structure is a necessary precursor to facilitate microstructural evolution and optimization during subsequent final hardening. Fine as-cast microstructures promote increased kinetic response during final hardening. Preliminary HT offers an additional degree of microstructural conditioning, accelerating the kinetics during final hardening. Austenitization temperatures and times were adjusted, facilitating increased dissolution and decomposition of carbides, ultimately enriching the alloy content of the matrix. As a result, the matrix hardness and strength were increased in comparison to conventionally hardened cast high speed steel roll material. A non-conventional approach was designed to optimize the response of the high speed material to HT.

 

A detailed microstructural evaluation was conducted on a series of radial samples from the shell of high speed steel (HSS) work rolls produced by centrifugal spin casting. Continuous local transformations were simulated using FEM and thermodynamic predictions. Microstructural observations from production rolls validated non-linear heat transient results and actual thermo-processing data. FEM sub-structuring and image processing techniques were implemented to aid in the development of a multi-scale model to simulate the local response of an individual microstructural constituents, i.e. carbides and/or matrix, under heat treatment (HT) conditions. The proper as-cast structure is a necessary precursor to facilitate microstructural evolution and optimization during subsequent final hardening. Fine as-cast microstructures promote increased kinetic response during final hardening. Preliminary HT offers an additional degree of microstructural conditioning, accelerating the kinetics during final hardening. Austenitization temperatures and times were adjusted, facilitating increased dissolution and decomposition of carbides, ultimately enriching the alloy content of the matrix. As a result, the matrix hardness and strength were increased in comparison to conventionally hardened cast high speed steel roll material. A non-conventional approach was designed to optimize the response of the high speed material to HT.

Keywords

HSS rolls; Carbide dissolution; Austenitization; Multi-scale modelling.

HSS rolls; Carbide dissolution; Austenitization; Multi-scale modelling.