Abstract
The principal categories of flow softening that occur at high temperatures are examined in turn. Two of these, substructure coarsening by dynamic recovery and dislocation elimination through the initiation of dynamic recrystallization, are types of work softening in that they involve reductions in dislocation density. Two further types, that of geometric softening and of adiabatic heating, do not involve the reversal of any strengthening mechanisms. The remainder of the flow-softening processes are associated with the rearrangement of second phases, e.g., spheroidization of lamellar structures, coarsening of precipitates, break-up of Widmanstatten and martensitic substructures, and phase redistribution during superplastic flow.
The practical implications of flow softening are discussed both during forming and under service conditions. It is shown that flow softening will lead to instabilities on compressive loading, and a simple construction is described which can be used to predict the onset and termination of the instability.
This is a preview of subscription content, log in via an institution to check access.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Preview
Unable to display preview. Download preview PDF.
References
Immarigeon, J.P. and Jonas, J.J., “The Deformation of ARMCO Iron and Silicon Steel in the Vicinity of the Curie Temperature”, Acta Met., 22 (1974), 1235–47.
Luton, M.J. and Jonas, J.J., “Solute Strengthening at High Temperatures in Zirconium-Tin Alloys”, Can. Met. Quart., 11 (1972), 79–90.
Hardwick, D. and Tegart, W.J.McG., “Structural Changes During the Deformation of Copper, Aluminum and Nickel at High Temperatures and High Strain Rates”, J. Inst. Metals, 90 (1961-62), 17–20.
Immarigeon, J.P., “High Temperature Deformation of ARMCO Iron and Silicon Steel in the Vicinity of the Curie Temperature”, unpublished Ph.D. dissertation, McGill University, 1974.
Jonas, J.J., Sellars, C M. and Tegart, W.J.McG., “Strength and Structure Under Hot Working Conditions”, Met. Rev., 14, No. 130 (1969), 1–24 in Metals Mater., 3 (1969), 33.
McQueen, H.J. and Jonas, J.J., “Recovery and Recrystallization During High Temperature Deformation”, in Plastic Deformation of Materials, R.J. Arsenault, ed., New York: Academic Press (1975), 393–493.
Immarigeon, J.P. and Jonas, J.J., “Flow Stress and Substructural Change During the Transient Deformation of ARMCO Iron and Silicon Steel”, Acta Met., 19 (1971), 1053–61.
Luton, M.J. and Sellars, CM., “Dynamic Recrystallization in Nickel and Nickel-Iron Alloys During High Temperature Deformation”, Acta Met., 17 (1969), 1033–43.
Rossard, C. and Blain, P., “Premiers résultats de recherches sur la déformation des aciers ä chaud mise au point d’un appareillage spécialement étudié”, Rev. Metall. (Paris), 55 (1958), 573–81.
Schmid, E., “Mechanical Strength and Plasticity of Metal Crystals”, Metallwirtschaft, 7 (1928), 1011–18. (in German)
Boas, W. and Schmitd, E., “Uber die Dehnung von Cadmiumkristallen”, Z. Phys., 54 (1929), 16–34.
Luton, M.J. and Holt, R., McGill University, 1974, unpublished research.
Hockett, J.E., “On Relating the Flow Stress of Aluminum to Strain, Strain Rate, and Temperature”, Trans. Met. Soc. AIME, 239 (1967), 969–76.
Samanta, S.K., “Dynamic Deformation of Aluminum and Copper at Elevated Temperatures”, J. Mech. Phys. Solids, 19 (1971), 117–35.
Robbins, J.L., Shepard, O.G. and Sherby, O.D., “Torsional Ductility and Strength of Iron-Carbon Alloys at Elevated Temperature”, ASM Trans. Quart., 60 (1967), 205–16.
Chojnowski, E.A. and Tegart, W.J.McG., “Accelerated Spheroidization of Pearlite”, Metal Sci. J., 2 (1968), 14–18.
Petkovic, R.A., “Recovery and Recrystallization of FCC Metals After High Temperature Deformation”, unpublished Ph.D. dissertation, McGill University, 1975.
Petkovic, R.A., Luton, M.J. and Jonas, J.J., “Recovery and Recrystallization of Carbon Steel Between Intervals of Hot Working”, Can. Met. Quart., 14 (1975), in press.
LeBon, A., Rofes-Vernis, J. and Rossard, C, “Recristallisation et précipitation provoquées par la déformation à chaud: cas d’un acier de construction sondable au niobium”, Mem. Soc. Rev. Metall., 70 (1973), 577–88.
Sastry, D.H., Luton, M.J. and Jonas, J.J., McGill University, 1974, unpublished research.
Abson, D.J. and Jonas, J.J., McGill University, 1971, unpublished research.
Luton, M.J. and Jonas, J.J., McGill University, 1974, unpublished reserach.
Dunlop, G.L. and Taplin, D.M.R., “The Tensile Properties of a Superplastic Aluminum Bronze”, J. Mater. Sci., 7 (1972), 84–92.
Chandra, T., “Flow and Fracture of Strain Rate Sensitive Copper Alloys”, unpublished Ph.D. dissertation, University of Waterloo, 1975.
Sagat, S., “The Deformation and Fracture of Superplastic Microsuplex Alloys”, unpublished Ph.D. dissertation, University of Waterloo, 1974.
Considére, A., “Memoire sur lTemploi du fer et de l1acier dans les construction”, Ann. Ponts Chausses, 6th Ser. 9, pt. 1 (1885), 574–775.
Author information
Authors and Affiliations
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 1978 Plenum Press, New York
About this chapter
Cite this chapter
Jonas, J.J., Luton, M.J. (1978). Flow Softening at Elevated Temperatures. In: Burke, J.J., Weiss, V. (eds) Advances in Deformation Processing. Springer, Boston, MA. https://doi.org/10.1007/978-1-4613-4024-9_7
Download citation
DOI: https://doi.org/10.1007/978-1-4613-4024-9_7
Publisher Name: Springer, Boston, MA
Print ISBN: 978-1-4613-4026-3
Online ISBN: 978-1-4613-4024-9
eBook Packages: Springer Book Archive