Grain Boundary Segregation of Impurities in Metals and Intergranular Brittle Fracture.

摘要

The results of several investigations relating to temper embrittlement of low-alloy steels by either Sb or P are summarized in this report. The most extensive investigation demonstrated that no grain boundary segregation of either alloying elements (Ni,Cr) or embrittling element (Sb) occurs during austenitizing or tempering at (650C). During tempering localized changes in composition of the ferrite immediately adjacent to a grain boundary occur. The chromium content is lowered and the nickel content is increased. During embrittlement,both nickel and antimony segregate at the boundary. A rapidly diffusing embrittling impurity (P) does not affect the segregation or embrittling effect of a more slowly diffusing impurity (Sb) during embrittlement. (Modified author abstract)