当前位置: X-MOL 学术Int. J. Fatigue › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Long solidification time effect on solution strengthened ferritic ductile iron fatigue properties
International Journal of Fatigue ( IF 5.7 ) Pub Date : 2021-01-05 , DOI: 10.1016/j.ijfatigue.2020.106137
T. Borsato , P. Ferro , A. Fabrizi , F. Berto , C. Carollo

Nowadays, lightweight design, aimed at reducing the eco-impact of mechanical components, is considered imperative and it asks for ever novel materials. In this scenario, solution strengthened ferritic ductile irons, thanks to their good combination of strength and ductility, are a potential alternative to the more expensive light alloys. Their unique properties come from a fully ferritic matrix solution hardened by high amounts of silicon ranging from 3 wt% to 4.3 wt%. Moreover, the fully ferritic matrix makes the alloy less sensitive to the hardness variation through the thickness and therefore more easily workable, compared to a ferritic-pearlitic cast iron of the same strength. With reference to heavy section castings, wind energy industry could take considerable advantage from this material in reducing the weights of heavy section components, provided that their mechanical properties, compared to those of separately cast samples with relatively thin wall, are well assessed. Keeping this challenge in mind, this work is aimed at characterizing the static and fatigue strength of a heavy section solution strengthened ferritic ductile iron casting. Static mechanical properties were found to decrease slightly with the increase of the solidification time. On the other hand, the fatigue resistance was reduced by 33% when the solidification time increased from 10 min to 10 h. Reasons were attributed to defects induced by long solidification times such as degenerate graphite and shrinkage porosities acting as crack initiation sites. Finally, a ‘master curve’ linking the solidification time with the fatigue strength is proposed as a design tool for designers who decide to exploit the potentialities of the investigated cast iron grade.



中文翻译:

凝固时间长对固溶强化铁素体球铁疲劳性能的影响

如今,旨在减少机械部件的生态影响的轻量化设计已成为当务之急,并且它需要不断创新的材料。在这种情况下,由于强度和延展性的良好结合,固溶强化铁素体球墨铸铁是较昂贵的轻合金的潜在替代品。它们的独特性能来自完全铁素体基体溶液,该溶液被3%至4.3 wt%的大量硅硬化。而且,与相同强度的铁素体-珠光体铸铁相比,全铁素体基体使合金对厚度范围内的硬度变化较不敏感,因此更易于加工。对于重截面铸件,风能行业可以从这种材料中获得相当大的优势,从而减轻重截面部件的重量,只要与具有相对薄壁的单独铸造样品相比,它们的机械性能得到了很好的评估。牢记这一挑战,这项工作旨在表征重截面溶液增强的铁素体球墨铸铁铸件的静态和疲劳强度。发现静态机械性能随凝固时间的增加而略有降低。另一方面,当固化时间从10分钟增加到10小时时,抗疲劳性降低了33%。原因归因于长时间的凝固所引起的缺陷,例如简并石墨和收缩孔隙作为裂纹的起始点。最后,

更新日期:2021-01-10
down
wechat
bug