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前言近几年来,孕育工艺由一次孕育发展为多次孕育,国外还提出了“型腔孕育法”,报导这方面的文章也越来越多。我们本着毛主席关于“人类总得不断地总结经验,有所发现,有所发明,有所创造,有所前进”的教导,试验了一种新的大块孕育法①。并经我厂初步生产实践证明,效果良好,现介绍如下。与此同时,根据我们试验和生产中的体会,谈谈对其他孕育方法的不同看法。 相似文献
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现代孕育铸铁的生产与孕育剂 总被引:4,自引:0,他引:4
孕育铸铁的生产已有数十年的历史,但长期来其生产方式一直是以降低碳、硅含量(碳当量)为基础,保证原铁水具有足够的过冷为前提,铁水经孕育处理后获得高强度灰口铸铁。所以,孕育剂基本上都是墨化剂。长期生产实践表明,采用低碳硅含量铁水生产 相似文献
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为了使灰铸铁得到较好的孕育效果,进行了孕育量的生产试验,认为降低出铁槽孕育剂加入量,同时增加随流孕育加入量是解决孕育衰退的最好方法;为了避免随流孕育量过大造成孕育剂不能完全熔解,选择了出铁槽0.3% 随流0.18%的孕育方式.介绍了孕育剂的选择、使用和贮存方法,特别提出了含Sr孕育剂解决缩松的局限性问题,以及孕育不良或过量对铸件品质的影响. 相似文献
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孕育剂在铁液中的熔化速度直接影响孕育处理的效果。熔化孕育剂的粒度是影响孕育剂熔化速度的重要因素之一。目前孕育剂的粒度是用筛网号分级的,而同一筛号、但具有不同颗粒形态的孕育剂体积和表面积与体积比是不同的,因而它们熔化速度也就不同。因此,生产和使用孕育剂时,在控制其粒度的同时,还应对其形态加以控制。 相似文献
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铸铁用孕育剂虽然种类繁多,但就世界范围而育,仍以铸造75硅铁的应用最为广泛。据统计,美国铸造75硅铁的使用量占该国孕育剂使用总量的75%。为提高75硅铁的育孕效果,不少国家对铸造用75硅铁中的钙、铝含量对铸铁孕育效果的影响做了较系统的研究,并推荐了合适的含量。我国铸铁生产使用的铸造75硅铁孕育剂均是按冶金部的标准生产的,仅就铝、硅提出要求,这并不能满足铸铁生产的要求。用铸造75硅铁处理铁水存在着孕育效果不稳定、石墨化能力不强、易出现针孔、孕育衰退快等问题。为了解国内使用铸造75硅铁的情况,我们收集了部分硅铁样品进行化学分 相似文献
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综述了球墨铸铁各种化学元素的作用和成分的控制范围,详细介绍了球墨铸铁的球化与孕育处理工艺。分析了单加纯Mg或RE合金作为球化剂的缺点,说明球化剂应以Mg为主、以RE为辅的原因;对冲入法、盖包法、喂丝法等球化处理工艺的优缺点进行了比较。指出了孕育处理对球墨铸铁生产的重要性,列举了球墨铸铁常用孕育剂的成分范围,并介绍了炉前一次孕育和多次孕育、瞬时孕育、随流孕育的特点。 相似文献
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Zhang Xipeng Kou Guojun Wu Chunjing Gan Zhaiping Zhao Wanzi Chuan Xiangzhao Ma Ye 《中国铸造》2008,5(2):95-98
The effect of ferrovanadium inoculation on the microstructure and properties of high speed steel (HSS) used for rolls was studied. The results showed that the as-cast eutectic carbide network tends to be broken after ferrovanadium inoculation, and the carbides are changed to rod-like or nodular shape. After heat treatment, the carbides in the inoculated HSS are spheroidized and distributed more uniformly in the matrix. The impact toughness of high speed steel with ferrovanadium inoculation is obviously improved. The action mechanism of ferrovanadium inoculation on the microstructure of the alloy is also discussed. 相似文献
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The eriect of ferrovanadium inoculation on the microstructure and properties of high speed steel (HSS)used for rolls was studied.The results showed that the as-cast eutectic carbide network tends to be broken after ferrovanadium inoculation,and the carbides are changed to rod-like or nodular shape.After heat treatment,the carbides in the inoculated HSS are spheroidized and distributed more uniformly in the matrix.The impact toughness of high speed steel with ferrovanadium inoculation is obviously improved.The action mechanism of ferrovanadium inoculation on the microstructure of the alloy is also discussed. 相似文献
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The effect of addition of 0.05wt.% to 0.25 wt.% Ca, Zr, Al-FeSi alloy on in-ladle and in-mould inoculation of grey cast irons was investigated. In the present paper, the conclusions drawn are based on thermal analysis. For the solidification pattern, some specific cooling curves characteristics, such as the degree of undercooling at the beginning of eutectic solidification and at the end of solidification, as well as the recalescence level, are identified to be more influenced by the inoculation technique. The degree of eutectic undercooling of the electrically melted base iron having 0.025% S, 0.003% AI and 3.5% Ce is excessively high (39 - 40℃), generating a relatively high need for inoculation. Under these conditions, the in-mould inoculation has a more significant effect compared to ladle inoculation, especially at lower inoculant usage (less than 0.20 wt.%). Generally, the efficiency of 0.05wt.% - 0.15wt.% of alloy for in-mould inoculation is comparable to, or better than, that of 0.15wt.% - 0.25wt.% addition in ladle inoculation procedures. In order to secure stable and controlled processes, representative thermal analysis parameters could be used, especially in thin wall grey iron castings production. 相似文献