Abstract
Estimation method of tensile plastic strain of austenite stainless steel by eddy current signal was examined. Tensile strain was applied to the test piece of austenite stainless steel of SUS304 and SUS316 with 20mm wide, lmm and 5mm thick. Eddy current testing was carried out to measure the difference in signals of the test piece with different applied strain. Eddy current signal increased with increase in plastic strain of the test piece. Increase rate of eddy current signal on SUS304 was greater than SUS316. Thickness also affects the correlation of strain and eddy current signal. Signal change with 5mm thick is larger in SUS304, and smaller in SUS316. Strain-induced martensite in SUS304 occurs eddy current signal change, and only surface roughness or slight thickness change affect the eddy current signal in SUS316.
