Showing 2 results for ZAREI HANZAKI A.
Dehghan Manshadi A., Zarei Hanzaki A., Golmahalleh O.,
Volume 2, Issue 2 (Jan 2005)
Abstract
The presence of bainite in the microstructure of steels to obtain a proper combination of strength and toughness has always been desired. The previous works however have shown that the presence of preferred bainite morphologies in the microstructure of any steel would not be readily accessible. In addition, the appearance of different bainite morphologies in the microstructure of any steel is dictated by different factors including the steel initial microstructure, austenitization characteristics, thermomechanical processing parameters and so on. Accordingly, in the present work, the effect of prior austenite grain size and the amount of austenite hot deformation on the bainite formation characteristics were investigated in 0.12C-2.5 Ni-1.2Cr steels. The results indicated that the prior austenite grain size and the amount of deformation in the austenite no-recrystallization region resulted in significant changes of the bainite formation kinetics and morphology.
Nosrati F., Zarei Hanzaki A.,
Volume 3, Issue 3 (Jul 2006)
Abstract
TRIP (TRansformation- lnduced- Plasticity) behavior is a powerful mechanism to improve mechanical properties. The basis of TRIP phenomena is the transformation of retained austenite with optimum characteristics (volume fraction, stability, size and morphology) to martensite during deformation at room temperature. Accordingly, the first requirement to obtain desired TRIP effects is to produce an appropriate microstructure. Thermo mechanical processing is an effective method to control the microstructural evolution thereby mechanical properties in TRIP steels. This work deals with a TRIP steel containing 0.2% C, evaluating the effects of straining before and during ?®a atransformation on its final characteristics, using hot compression tests. The results revealed that straining in the two phase region (dynamic transformation) not only reduces the ferrite grain size more significantly, but also increases the retained austenite volumefraction. Accordingly the final mechanical properties were also improved.
