Undercooling and nodule count in thin walled ductile iron castings

Karl Martin Pedersen, Niels Skat Tiedje

    Research output: Chapter in Book/Report/Conference proceedingArticle in proceedingsResearchpeer-review

    Abstract

    Casting experiments have been performed with eutectic and hypereutectic castings with plate thick¬nesses from 2 to 8 mm involving both temperature measurements during solidification and micro¬structural examination afterwards. The nodule count was the same for the eutectic and hypereutectic castings in the thin plates ( 4.3 mm) while in the 8 mm plate the nodule count was higher in the hypereutectic than in the eutectic castings. The minimum temperature prior to the eutectic recalescence (Tmin) was 15 to 20C lower for the eutectic than the hypereutectic castings. This is due to nucleation of graphite nodules which begins at a lover temperature in the eutectic than in the hypereutectic castings The recalescence (Trec) was however also larger for the eutectic casting and in the thin plates the maximum temperature after recalescence (Tmax) was the same in the eutectic and hypereutectic plates. This is due to that higher undercooling gives higher driving force for the solidification process and the equal nodule counts therefore give the same Tmax. The higher undercooling before recalescence increases however the risk for formation of carbides during the solidification. In the 8 mm plates the lower nodule count in the eutectic plates gave also a lower Tmax than in the hypereutectic castings.
    Original languageEnglish
    Title of host publicationSolidification Processing 2007 : Proceedings of the 5th decennial international conference on solidification processing
    EditorsHoward Jones
    Place of PublicationGreat Britain
    PublisherDepartment of Engineering Materials, University of Sheffield
    Publication date2007
    Pages456-461
    ISBN (Print)0952250748
    Publication statusPublished - 2007
    Event5th decennial international conference on solidification processing - Sheffield, Great Britain
    Duration: 1 Jan 2007 → …

    Conference

    Conference5th decennial international conference on solidification processing
    CitySheffield, Great Britain
    Period01/01/2007 → …

    Cite this

    Pedersen, K. M., & Tiedje, N. S. (2007). Undercooling and nodule count in thin walled ductile iron castings. In H. Jones (Ed.), Solidification Processing 2007: Proceedings of the 5th decennial international conference on solidification processing (pp. 456-461). Department of Engineering Materials, University of Sheffield.