Cr-Ni-Mo-Al-Tiマルエージング鋼のTRIP挙動に関する実験的考察

TRIPひずみと背応力の進展について

抄録

Evolution of the TRIP strain and the back stress in a maraging TRIP steel (MAVAL X12) is studied experimentally. The stress holding tests under cooling are carried out in order to measure the TRIP performance of the steel in both the axial and shear directions. A linear Greenwood-Johnson relation is observed in the low applied stress range between the maximum value of the TRIP strain and the applied hold stress, being irrelevant to the direction of the applied stress. At the higher applied stress range, the relation becomes non-linear, and depends on the direction of applied stress. When the applied stress is unloaded down to the value of the back stress in the process of transformation, the strain response just after unloading reveals qualitatively that the back stress evolves during transformation from its initial value. The backflow after unloading is due to the Magee effect.