Fellow engineer, Westinghouse Research and Development Center, Pittsburgh, Pa.
Pages: 17 Published: Jan 1979
The effect of microstructural variations produced by varying the transformation product and the tensile strength level on the temper embrittlement susceptibility of steels has been the subject of some recent studies. A review of the results pertaining to chromium molybdenum (Cr-Mo), chromium-molybdenum-vanadium (Cr-Mo-V), and nickel-chromium-molybdenum-vanadium (Ni-Cr-Mo-V) steels has been completed. Based on the review, it appears that in 2.25Cr-1Mo steels embrittled by step-cooling the transformation product does not appreciably affect the temper embrittlement susceptibility. In Cr-Mo-V and Ni-Cr-Mo steels, susceptibility to embrittlement increases in the order ferrite-pearlite, bainite, and martensite. Results on the effect of strength levels are inconclusive. In general, those structures that cause the steel to have low toughness initially also result in reduced susceptibility for further embrittlement. The limited amount of Auger data available suggest that the effect of microstructure is explainable, at least in part, by differences in grain boundary segregation of impurity elements caused by differences in microstructure.
steels, microstructure, alloys, temper embrittlement
Paper ID: STP36869S