抄録
The effects of strain rate and aging on the tensile property of high-purity Fe–50 mass%Cr and 166 mass ppm carbon-doped Fe–50 mass%Cr alloys were investigated by tensile tests and microstructural observations. The serration occurring by dynamic strain aging on the stress-strain curves disappears at the strain rate below 4.2×10−5 s−1 and above 1.7×10−2 s−1 at 773 K in a high-purity Fe–50 mass%Cr alloy with the grain size of 29 \\micron. The deformation twinning in a high-purity Fe–50 mass%Cr alloy with the grain size of 108 \\micron at 773 K occurs at the same stress of 480 MPa, independent of strain rate. The pre-strained specimen of high-purity Fe–50 mass%Cr alloy shows static strain aging after aging at 573 K . The aging treatment at 773 K causes the precipitation of carbides and thereby the formation of deformation twins in tensile tests. In a carbon-doped high-purity Fe–50 mass%Cr alloy, the heat treatment for precipitating carbides on grain-boundaries restrains the formation of deformation twins at 773 K.
