S-N Fatigue Behavior of Fe25Mn Steel and Its Weld at 298 and 110 K

초록

The S-N fatigue behavior of newly developed Fe25Mn steel, including base metal and butt-welded joint, was investigated at 298 and 110 K, and the results were compared to those of previously reported Fe16Mn2Al and STS304L steels. Fe25Mn steel has quite promising fatigue performance at 298 K and even at 110 K, showing comparable resistance to fatigue to STS304L. The S-N fatigue behavior of Fe25Mn steel was dependent on tensile strength at 298 and 110 K, the trend of which well agreed to that of other austenitic steels. The electron backscatter diffraction and micrographic analyses suggested that transformation induced plasticity and twinning induced plasticity effects did not occur in Fe25Mn steel under fatigue loading at room and cryogenic temperatures. The butt-welded Fe25Mn/Fe25Mn and Fe25Mn/STS304L specimens also showed a satisfactory fatigue behavior which was even comparable to that of STS304L/STS304L specimen at 110 K. The S-N fatigue behavior of Fe25Mn steel and its welds was discussed based on the fractographic and microscopic observations.

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