Fundamental Study on the Reheat Crackings in Steels (Part 5)

Effect of Antimony on the Crack Initiation Stress at Grain Boundary

Abstract

The effect of antimony on the intergranular crack initiation stress at 600°C was investigated to clarity the mechanism of reheat cracking.
Two kinds of steels were used, one was crack sensitive A387-12, the other one was insensitive A533B-Class 1.
It is concluded that in these steels, antimony atoms segregate to prior austenite grain boundaries of simulated weld thermal cycle zone (peak temp.; 1350°C, 800°C to 500°C; 10 sec) during heating up to 600°C, and that the cohesive strength of grain boundary decreases in proportion to the content of segregated antimony.