The Effect of Core and Carburized Surface Microstructural Stability on Residual Stress Evolution during Tempering

    Volume 6, Issue 9 (October 2009)

    ISSN: 1546-962X

    CODEN: JAIOAD

    Published Online: 29 October 2009

    Page Count: 8


    Vatavuk, Jan
    Metallurgical EngineerMaster of Metallurgical EngineeringDoctor of Metallurgical and Materials EngineeringProfessor, Univ. of São Paulo (USP)Dept. of Materials Engineering, Presbiteriana Mackenzie Univ., São Paulo, São Paulo

    di Monte, Mariana Zicari
    Materials Engineer, Presbiteriana Mackenzie Univ., São Paulo, São Paulo

    Couto, Antonio Augusto
    Metallurgical EngineerMaster and Doctor of Science in Nuclear Materials Technology Area, Presbiteriana Mackenzie Univ., São Paulo, São Paulo

    (Received 9 May 2008; accepted 15 July 2009)

    Abstract

    It is a well-known fact that compressive residual stresses are developed during the quenching process of carburized parts. The main purpose of this work is related to the tempering effects on as-quenched compressive residual stresses of commercial carburized samples. The work was carried out by using SAE 4120 RH steel samples with different diameters (15 and 38 mm), which led to different cooling rates with a direct effect on the nucleus microstructure. The carburized surface microstructure was considered similar. The 15 mm bars nucleus microstructures were predominantly martensitic but bainitic in the larger samples. The as-quenched surface compressive residual stress was lower in the smaller diameter samples. The compressive residual stress reduction due to increasing tempering temperature was continuous for the larger diameter work piece. The smaller diameter samples had different behaviors in two regions; the compressive stress for lower tempering temperatures was reduced, while values were enhanced over higher temperatures.


    Paper ID: JAI101881

    DOI: 10.1520/JAI101881

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    Author
    Title The Effect of Core and Carburized Surface Microstructural Stability on Residual Stress Evolution during Tempering
    Symposium , 0000-00-00
    Committee E28