高硅铸钢残余奥氏体分布形态和其对力学性能的影响.pdfVIP

b Vol No Y C ACTA METALLURGICA SINICA Mar pp UKOMSI a kDiVyJpdFeHl W Q GfN TEM syVaMuWCwfNZyVa MZhuNHQwwjQwwC gwTu KS wXxYwHwweWzZ wqXwoOuXwsQwwYw V V j F B syVaMX Z TG TG BG A BX MORPHOLOGY OF RETAINED AUSTENITE AND ITS EFFECTS ON THE MECHANICAL PROPERTIES OF HIGH SILICON CAST STEEL CHEN Xiang LI Yanxiang Key Lab oratory for Advanced Materials Pro cessing Technology Ministry of Education of China Department of Mechan ical Engineering Tsinghua University Beijing Correspondent CHEN Xiang lecturer Tel Email xchentsinghuaeducn Supported by Laboratory Found of Tsinghua University No Manuscript received in revised form ABSTRACT The microstructure and morphology of retained austenite of austemp ered high silicon cast steel after various austemp ering combinations are investigated by TEM and the volume fraction of retained austenite is measured by XRD metho d The exp erimental results indicate that the retained wo typical morphologies lm austenite presented at the isothermal transformation temp erature has t shap ed and blo cky morphologies There is KS orientation relationship b etween the lm shap ed re tained austenite and bainite ferrite The lm shap ed retained austenite is favorable to improve strength and toughness of the cast steel but the blo cky retained austenite has p o or mechanical stability and thus is detrimental to the mechanical prop erties of the steel It is suggested that the ratio of volume fraction of the lm shap edblo cky retained austenite V V must exceed ab out for optimum