Property enhancement of cast iron used for nuclear casks  

作　　者：R.K. Behera B.P. Mahto J.S. Dubey S.C. Mishra S. Sen 

机构地区：[1]Department of Metallurgical and Materials Engineering, National Institute of Technology Rourkela, Odisha 769008, India [2]Bhaba Atomic Research Centre (Post Irradiation Examination Division), Mumbai 400085, India

出　　处：《International Journal of Minerals,Metallurgy and Materials》2016年第1期40-48,共9页矿物冶金与材料学报（英文版）

基　　金：the Board of Research in Nuclear Science (Project Grant No. 2011/36/18-BRNS), India for carrying out this investigation

摘　　要：Ductile iron （DI） is a preferred material for use in various structural, automotive, and engineering fields because of its excellent combination of strength, toughness, and ductility. In the current investigation, we elucidate the relationship between the morphological and mechanical properties of DI intended for use in safety applications in the nuclear industry. DI specimens with various alloying elements were subjected to annealing and austempering heat treatment processes. A faster cooling rate appeared to increase the nodule count in austempered specimens, compensating for their nodularity value and subsequently decreasing their ductility and impact strength. The ductility and impact energy values of annealed specimens increased with increasing ferrite area fraction and nodularity, whereas an increase in the amounts of Ni and Cr resulted in an increase of hardness via solid solution strengthening. Austempered specimens were observed to be stronger than an- nealed specimens and failed in a somewhat brittle manner characterized by a river pattern, whereas the ductile failure mode was character- ized by the presence of dimples.Ductile iron （DI） is a preferred material for use in various structural, automotive, and engineering fields because of its excellent combination of strength, toughness, and ductility. In the current investigation, we elucidate the relationship between the morphological and mechanical properties of DI intended for use in safety applications in the nuclear industry. DI specimens with various alloying elements were subjected to annealing and austempering heat treatment processes. A faster cooling rate appeared to increase the nodule count in austempered specimens, compensating for their nodularity value and subsequently decreasing their ductility and impact strength. The ductility and impact energy values of annealed specimens increased with increasing ferrite area fraction and nodularity, whereas an increase in the amounts of Ni and Cr resulted in an increase of hardness via solid solution strengthening. Austempered specimens were observed to be stronger than an- nealed specimens and failed in a somewhat brittle manner characterized by a river pattern, whereas the ductile failure mode was character- ized by the presence of dimples.

关 键 词：ductile iron NODULARITY mechanical properties failure modes nuclear industry 

分 类 号：TG143[一般工业技术—材料科学与工程]