DYNAMIC STRAIN-AGING INFLUENCE ON THE CYC LIC BEHAVIOR OF FERRITIC STAINLESS-STEEL TYPE AISI 430F

Austenitic and ferritic stainless steels possess a number of desirable properties. Recently, ferritic-martensitic together with the AISI 316 stainless steels have been focused on as the leading candidates of th e structural materials for fusion reactors technology. As a part of an extensive fatigue investigation of ferritic-martensitic stainless ste els, the cyclic strain softening/hardening behavior have been studied in a commercial ferritic type AISI 430F stainless steel. In this work attention is paid on the strain aging effects on the fatigue life of t he material. Cyclic hardening curves obtained by plotting the peak ten sile stress of the histeresis loop against the number of cycles showed a general behaviour strongly dependent on the temperature. However, i n the range from 723K to 823K an anomalous hardening behaviour appeare d. This effect can be rationalized by dislocation-solute atoms interac tions.