Low-cycle fatigue behavior of thermal-barrier-coated SUS304 stainless steel at elevated temperature

To clarify the effects of thermal barrier spraying on the fatigue behavior of materials, low-cycle fatigue tests of thermal barrier-coated SUS304 stainless steel were performed under strain-controlled condition at 973 K. Triangular strain waveform and tension or compression hold trapezoidal waveform were adopted. From the experimental results, decrease of fatigue of the steel was observed under triangular strain wave as compared with that of the base metal. On the other hand, fatigue life of the coated one under trapezoidal wave was same as that of the uncoated one. Difference of fatigue life between coated and uncoated material was explained by crack initiation behavior, which was obtained by A. C. potential method and optical microscopy.