GS36 Creep Property Evaluation of 12%Cr Ferritic Steel Welded Joint by Modified SP Creep Test

Abstract

Modified small punch (SP) creep test with a rectangular-type specimen (10 X 6 X 0.5 mm) was applied to the interrupted uniaxial creep specimen of welded joint ofKA-SUS410J3 (t/t_r=93%). The specimens consisting of weld metal, heat affected zone and base metal were removed at the different distances from the surface. All of the specimens were subjected to the SP creep test at 600°C and 250 N. Experimental results revealed that the SP creep properties deteriorated by the uniaxial creep and the deterioration was pronounced at around the surface of the interrupted creep specimen. The distribution of the decrease in SP creep strength throughout the thickness was qualitatively in good agreement with that of the area fraction of creep void. It was also found by the life fraction rule that the region just below the surface already consumed almost all the life, whereas the life fraction was determined to be about 70% at the central region of the thickness.