Recent advances in hot working: fundamental dynamic softening mechanisms

• Published in: Journal of applied metalworking 1984-07, Vol.3 (3), p.233-241
• Main Authors: MCQUEEN, H.J, JONAS, J.J
• Format: Article
• Language: English
• Subjects: Applied sciences; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Forging and extrusion; Forming; Materials science; Metals. Metallurgy; Phase diagrams and microstructures developed by solidification and solid-solid phase transformations; Physics; Production techniques
• ISSN: 0162-9700; 2168-8125
• DOI: 10.1007/BF02833651

Important aspects of the fundamental mechanisms of hot working, dynamic recovery and recrystallization and their influence on alloying additions are considered. The fundamental mechanisms responsible for the low rate of strain hardening during high-temp. deformation and for a steady state of flow at high strains are confirmed to be: dynamic recovery, which limits the accumulation of dislocations through annihilations and operates at all strains in all metals, and dynamic recrystallization, which eliminates dislocations through the migration of grain boundaries and which operates beyond a critical strain when the dislocation density becomes high enough to give rise to the nucleation and growth of new grains. These softening processes are retarded by the presence of solute atoms and second-phase particles which reduce the mobility of dislocations and high-angle boundaries. As a result of the high strains imposed there is much more microstructural change than during creep loading. 143 ref.--C.M.L.S.