STP956: Impurity Element Effects on the Toughness of 12 Cr-1 Mo Steel

    Rou, SH
    Graduate students and professor, Auburn University, Auburn, AL

    Harrelson, KJ
    Graduate students and professor, Auburn University, Auburn, AL

    Wilcox, RC
    Graduate students and professor, Auburn University, Auburn, AL

    Pages: 8    Published: Jan 1987


    Abstract

    The effects of the trace impurity elements, phosphorus, sulfur, and silicon, on the impact toughness of a 12 Cr-1 Mo steel were investigated. The results of Charpy impact tests showed that the additions of all three elements produced an increase in the ductile-brittle transition temperature and the addition of phosphorus or sulfur caused a decrease in the upper shelf energy. Impurity segregation is used to explain the effect of phosphorus. The higher silicon concentrations produced increased amounts of delta ferrite, which is detrimental to toughness. Sulfur promotes nonmetallic inclusions and delta ferrite, both of which can result in embrittlement.

    Keywords:

    ferritic steels, impact toughness, phosphorus, sulfur, silicon, mechanical properties


    Paper ID: STP25645S

    Committee/Subcommittee: E10.07

    DOI: 10.1520/STP25645S


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