Effects of dual-cracks on the creep crack growth behaviour of HastelloyC276-BNi2 brazed joints.

In this paper, the effects of dual-cracks on the CCG behaviour of Hastelloy C276-BNi2 brazed joints were investigated. And the effects of inner crack length, inner crack distance and mismatched material coefficients on the creep crack initiation (CCI) time, CCG rate and creep life were also discussed. The results show that the creep crack can across over the inner crack and propagates continuously. The brazing defects can accelerate the CCG rate, thus leading to the decrease in the creep life and CCG length. With the increases in inner crack length and the decreases in inner crack distance, the CCI time, creep life and CCG length decrease. Longer inner crack distance and shorter defect length can suppress creep crack initiation and propagation. Bigger mismatch factor between base metal and filler metal may avoid the weakening effects of brazing defect on creep life. [ABSTRACT FROM AUTHOR]