Temperature transients during hot pack rolling of high temperature alloys

An investigation establishes and verifies a simple method to estimate temperature transients during hot pack rolling. This method accounts for temperature losses during pack transfer between a furnace and the rolling equipment, and chilling effects that occur during deformation within the roll gap. The efficacy of the model was confirmed by comparison of predicted rolling pressures to measurements for a conventionally rolled near- gamma titanium aluminide. It is concluded that substantial heat losses occur during transfer of the pack to the mill and during rolling itself. Temperature transients during hot pack rolling of materials whose flow stresses are very sensitive to temperature are mirrored by rolling load signatures. The low rolling speeds /deformation rates that may be necessary to fabricate hard-to-work alloys can lead to temperature rundown effects or longitudinal variations of temperature that may give rise to non-uniformities in as-rolled microstructure and properties.