INTERGRANULAR FRACTURE OF A HIGH PURITY IRON DUE TO OXYGEN.

Abstract

As the oxygen concentration was increased by increasing the doping temperature (873, 973 and 1073 K), elongation to fracture at 4. 2 K decreased. Specimens which are doped with oxygen at 973 and 1073 K and fracture along grain boundaries without any appreciable elongation are completely ductile at 20 K. If well-decarburized and not doped with oxygen, commercial high purity iron (Johnson-Matthey iron) is more susceptible to IGF than high purity iron. The results show that oxygen segregated at grain boundaries weakens the grain boundary cohesion to some extent, but the effect is not large.