高品质球墨铸铁生产的原材料选择和微量元素控制

Selection of Raw Materials and Control of Trace Elements in the Production of High-Quality Ductile Iron

在球墨铸铁的生产过程中,原材料的选择和化学成分的控制非常重要。在早期的球墨铸铁生产时期,许多人已经研究了微量元素与石墨形态及基体组织的作用。由于微量有害元素对石墨的不利影响,所允许最高含量在过去的50年间逐年降低。本文回顾了文献中所建议的一些球墨铸铁中的微量干扰元素的最高含量,发现对于大多数的球墨铸铁铸造厂,仍然需要稀土元素来中和干扰元素的有害影响以提高球墨铸铁的质量。发现使用高纯和超高纯生铁非常有助于生产不同壁厚、要求高、安全性和结构复杂的以及大断面和超大断面的球墨铸铁件。采用高纯和超高纯生铁生产的球墨铸铁件具有优异的组织,其力学性能和动态性能比当前国际球墨铸铁标准高很多,需要进一步研究高纯、超高纯原铁液对球墨铸铁组织和性能的影响。

During the production of ductile iron,the selection of raw materials and control of chemical composition are very important.In the early period of ductile iron production,many people studied the effect of trace elements on graphite morphology and matrix structure.Due to the adverse effect of trace harmful elements on graphite,the maximum allowable content was decreased year by year in the past 50 years.This paper has reviewed some of the suggested ductile iron trace elements in the literature and in several Chinese foundries.It is found that for most ductile iron castings,rare earth elements are still required to neutralize the harmful effects of trace elements and improve ductile iron quality.It is also found that the use of high purity and ultra-high purity base iron melts enabled integrated,safety-critical and complicated ductile iron castings of varying thickness,and heavy-section,to be produced successfully.These ductile iron castings have surprisingly good structures,and their mechanical and dynamic properties are vastly superior to those specified in current international ductile iron standards.Further study is required on the effects of using high purity and ultra-high purity base melts on the structure and properties of ductile iron.