TEMPERATURE-DEPENDENCE OF THE DISSOCIATION WIDTH OF DISLOCATIONS IN ACOMMERCIAL 304L STAINLESS-STEEL

The dissociation width of dislocations in a commercial AISI 304L stain less steel was measured as a function of temperature. Two types of exp eriments were carried out. In one, specimens were deformed at room tem perature, followed by annealing at various temperatures, and in the ot her, specimens were deformed directly at various temperatures. In both experiments the width of near-edge dislocations remained unchanged up to 300-400-degrees-C, then decreasing gradually. On the other hand, th e width of near-screw dislocations showed the maximum at around 400-de grees-C, when specimens were deformed directly at high temperatures: W hen specimens were deformed at room temperature and then annealed at h igh temperatures, the maximum was less evident. The Suzuki segregation was invoked to explain behaviour of the dissociated dislocations in a commercial AISI 304L stainless steel. It is proposed that some typica l features of dynamic strain ageing observed at around 400-degrees-C s uch as enhanced work hardening and planar slip could be caused in part and in conjunction with other more effective mechanisms than those ca used by the slightly enhanced dissociation width of near-screw disloca tions in the same temperature range.