Please use this identifier to cite or link to this item: http://hdl.handle.net/1959.3/47626

Title

Analysis of secondary oxide-scale failure at entry into the roll gap

Author(s)

Krzyzanowski, M.;  Beynon, J. H.;  Sellars, C. M.

Abstract

Both numerical analysis based on finite-element (FE) modeling and experimental evidence concerning the secondary oxide-scale failure at entry into the roll gap are presented and reviewed for a better understanding of events at the roll-workpiece interface, in turn, leading to better definition of the boundary conditions for process models. Attention is paid to the two limit modes leading to oxide-scale failure, which were observed earlier during tensile testing under rolling conditions. These are considered in relation to the temperature, the oxide-scale thickness, and other hot-rolling parameters. The mathematical model used for the analysis is composed of macro and micro parts, which allow for simulation of metal/scale flow, heat transfer, cracking of the oxide scale, as well as sliding along the oxide/metal interface and spallation of the scale from the metal surface. The different modes of oxide-scale failure were predicted, taking into account stress-directed diffusion, fracture and adhesion of the oxide scale, strain, strain rate, and temperature. Stalled hot-rolling tests under controlled conditions have been used to verify the types of oxide-scale failure and have shown good predictive capabilities of the model. The stock temperature and the oxide-scale thickness are important parameters, which, depending on other rolling conditions, may cause either through-thickness cracking of the scale at the entry or lead to entry of a nonfractured scale when the scale/metal interface is not strong enough to transmit the metal deformation.

Publication type

Journal article

Source

Metallurgical and Materials Transactions B: Process Metallurgy and Materials Processing Science, Vol. 31, no. 6 (Dec 2000), pp. 1483-1490

Publication year

2000

Keyword(s)

Failure;  FE modelling;  Finite element method;  Heat transfer;  Interfaces;  Mathematical models;  Materials;  Metal-oxide interface;  Metals;  Oxides;  Secondary oxide scale failure;  Strain;  Temperature;  Tensile testing

Publisher

Springer

ISSN

1073-5615

Publisher URL

http://dx.doi.org/10.1007/s11663-000-0033-z

Peer reviewed