Fracture Toughness in Synthetic Weld-Heat Affecte Zone of Steels for Low Temperature Survice (Report I)
1981 Volume 50 Issue 10 Pages 1008-1012
Details
1981 Volume 50 Issue 10 Pages 1008-1012
Fracture toughness, JIc in synthetic weld-heat affected zone of Al killed steel and its recovery by following reheating were investigated by three point bend test in low temperature range. Synthetic weld-heat affected zone was obtained by rapid heating at peak temperature 1250°C or 1350°C and by cooling for 10 sec or 80 sec from 800°C to 500°C. Following reheating was given by rapid heating at peak temperature from 700°C to 1000°C and by cooling for 10 sec or 80 sec from 800°C to 500°C. Main results obtained were as follows.
(1) JIc, values in synthetic HAZ were inferior to those of as-received steel in every test temperature.
(2) Remarkable recovery of JIc value was obtained in a synthetic HAZ heated at 1350°C and cooled for 10 sec from 800°C to 500°C, by following heating at 700°C and cooling for 53 sec from 700°C to 500°C, due to form tempered martensite and bainite structure mainly.
(3) Maximum JIc, was obtained to Tc=20 sec, changing cooling time, Tc from 800°C to 500°C in a synthetic HAZ heated at peak temperature 1350°C.
(4) Hall-Petch relation of JIc vs L-1/2 was recognized between JIc and facet size, L.
