Free cutting steel consists of two types, one for machine structural use and the other based on low carbon steel for hard cutting, such as SAE 12L14. Conventionally, Pb has been added to free cutting steels to improve their machinability, but Pb in steel is thought to have a harmful effect on the human body. Therefore, as alternatives to Pb addition in free cutting steels, JFE Steel and NKK BARS & SHAPES studied graphite precipitation in the steel and control of the sulfide morphology by the chemical composition and developed new Pb-free free cutting steels based on these respective concepts. In the graphite-type free cutting steel for machine structural use, JFE Steel realized machinability equal to that of the Pb-added steel by controlling the state of existence of C in the steel, and achieved an excellent balance of cold workability and high fatigue strength after quenching and tempering. As a substitute for the low carbon Pb-added free cutting steel (SAE 12L14), NKK BARS & SHAPES developed a steel with improved machinability by crystallizing large sulfide inclusions, which is realized by increasing S addition while also adding Cr on the basis of the estimation from the calculated phase diagrams. (Engl. translation from JFE GIHO, 2004, No.4, p.64-69, (jap.))


    Access

    Access via TIB

    Check availability in my library

    Order at Subito €


    Export, share and cite



    Title :

    Bar and wire steels for gears and valves of automobiles - Eco-friendly free cutting steel without lead addition


    Additional title:

    Stabstahl und Stahldraht für Fahrzeugzahnräder und -ventile - Ökologisch freundlicher Automatenstahl ohne Bleizusatz


    Contributors:

    Published in:

    Publication date :

    2004


    Size :

    7 Seiten, 11 Bilder, 3 Tabellen, 11 Quellen



    Type of media :

    Article (Journal)


    Type of material :

    Print


    Language :

    English




    Development of Free Cutting Steel without Lead Addition to Substitute SAE12L14

    Murakami, T. / Tranita, K. / Shiraga, T. et al. | British Library Conference Proceedings | 2008


    Steering gears for automobiles

    Lemp, Herman | Engineering Index Backfile | 1902



    Steels for automobiles and aeroplanes

    Hatfield, W.H. | Engineering Index Backfile | 1930


    Steels for automobiles and aeroplanes

    Hatfield, W.H. | Engineering Index Backfile | 1929