INTERACTION OF COHERENT NANOSCALE PRECIPITATES WITH SCREW DISLOCATIONS TO LOWER THE PEIERLS STRESS IN LOW CARBON STEELS

摘要

Low carbon steels with nanosize bcc copper precipitates have remarkably high Charpy fracture energies at cryogenic temperatures. This is attributed to a reduction in the activation energy for nucleating double kinks on screw dislocation in iron from interaction of slightly misfitting coherent coplanar precipitates with screw dislocations. The theory of such interaction is discussed.