EFFECTS OF STRAIN RATE HISTORY ON THE STRAIN AGEING PHENOMENA IN AISI 316 STAINLESS STEEL
Austenitic stainless steels are frequently used in the construction of both nuclear and non-nuclear energy systems, where safety and economy are of great concern. This makes it essential to understand and describe their flow and fracture characteristics under all possible thermomechanical histories, which incorporate large excursions in strain rate and temperature, reverse and cyclic loadings, and multiaxial stress systems. In the present paper, recent results are reported on the stress-strain characteristics of AISI 316H SS as obtained from monotonic and interrupted tensile tests involving a strain-rate change of six orders of magnitude, from 10- 3- to 103 s-1 and vice versa, at seven different temperatures ranging from the ambient to 650 degrees C. The quasi-static portion of the imposed strain-rate history was conducted on a Hounsfield tensometer, whereas the dynamic testing was performed on a modified tensile split Hopkinson bar. Static strain ageing was observed at all temperatures, particularly in tests involving dynamic prestraining followed by quasi-static reloading to fracture. On the other hand, dynamic strain ageing clearly manifested itself by all its well-known phenomenological characteristics in quasi-static testing performed at elevated temperatures between 400 and 650 degrees C. Both phenomena were affected to different degrees by the amount and the strain rate of prestraining, as well as by the testing temperature. The observed characteristics are compared with results reported in the literature, and attempts are made to rationalize the behaviour in the light of thermal activation theories.
Bibliographic Reference: STAINLESS STEELS '87, YORK (UK), SEPT. 14-16, 1987 WRITE TO CEC LUXEMBOURG, DG XIII/A2, POB 1907 MENTIONING PAPER E 33157 ORA
Availability: Can be ordered online
Record Number: 1989126044001 / Last updated on: 1989-01-01
Available languages: en