Effects of Accelerated Iso-Thermal Aging on Elastic-Plastic Fracture Toughness and Fracture Resistance Curve by Unloading Compliance Method in SA533B Low Alloy Steel

J. Ocean Eng. Technol. 1994;8(2):157-165.

제하 컴플라이언스법에 의한 SA533B강의 $J_1C$ 및 J-R 곡선에 미치는 열시효 영향

윤한기,차귀준

동의대학교 공과대학기계설계학과,동명전문대학 가스냉동과

Keywords: Accelerated Iso-Thermal Aging, Blunting line, Elastic-Plastic Fracture Resistance Curve, Unloading Compliance, Apparent Negative Crack Growth, Offset technique

핵심용어: 열시효, 둔화직선, 탄소성 파괴저항곡선, 제하 컴플라이언스, 균열길이감소현상, 오프세트법

Abstract

Effect of an accelerated iso-thermal aging (375 degree C x 66days, 375 degree C x 200days) on elastic-plastic fracture resistance curve were examined in SA533B low alloy steel. Fracture toughness test are conducted by unloading compliance method at room temperature. But the apparent negative crack growth phenomenon, usually arise in partial unloading compliance test. The phenomenon of negative crack growth may be eliminated by the offset technique. There is no effect of aging on J sub(IC) and dJ/da in iso-thermal aged (375 degree C x 66 days) specimen, but there is very little effect in iso-thermal aged (375 degree C x 200 days) specimen.