Neutron diffraction measurement during stress induced phase transformation

Harjo, S.   ; Tsuchida, Noriyuki*; Nakamoto, Tatsushi*; Aizawa, Kazuya  ; Abe, Jun*; Gong, W.

Stress Induced Phase Transformation is one of the strengthening mechanisms in steels for the improvement in strength and ductility, which is well known as a TRIP effect. Two kinds of steels, type 304 stainless steel and TRIP-type multiphase carbon steel, were used in neutron diffraction measurements during tensile deformations. The type 304 stainless steel samples were deformed at RT and at 50K. There was no TRIP effect observed during the deformation at RT, while TRIP effects were observed at the onset of plastic region during deformation at 50K. The TRIP-type carbon steel was deformed at RT, and TRIP effects started at the onset of plastic deformation. The phases formed during TRIP effects were determined and stress partitioning among the constituent phases were evaluated. The details will be reported and the strengthening mechanisms of both steels during the TRIP effects will be discussed in the presentation.