共查询到19条相似文献,搜索用时 390 毫秒
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用醇基防渗透砂状涂料解决渗透粘砂的研究 总被引:1,自引:0,他引:1
介绍了一种用于厚大铸钢件生产、防止渗透粘砂的新型醇基砂状涂料。这种涂料的主要耐火骨料是75~200目铬铁矿砂、镁砂、刚玉砂等。尽管它是一种醇基砂状涂料,但具有悬浮稳定性高,涂刷流畅,涂层强度好等特点。试验和生产应用都表明,该涂料不仅能起到防钢液渗透粘砂作用,有效地提高铸钢件的表面质量,而且能取代铬铁矿面砂工艺。还初步探讨了这种涂料的防渗透粘砂机理。 相似文献
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大型铸钢件用醇基剥离型涂料 总被引:1,自引:1,他引:0
为了适应大型铸钢件的生产,研制了水玻璃砂型(芯)用醇基剥离型涂料。涂料以94%以上浓度的乙醇为溶剂,可以点燃自干;以锆英粉为骨料,它与金属液不浸润,热膨胀系数小,可以获得均匀、连续的涂料层;以聚乙醇缩醛和海泡石为悬浮剂,以酚醛树脂和松香为粘结剂,以磷酸盐为高温粘结剂,用氧化铁为附加物,它在高温下能与硅砂形成铁橄榄石烧结层,可以有效地阻止金属液向砂型(芯)渗透,阻止粘砂缺陷的产生,获得表面光洁的大型铸钢件。 相似文献
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烧结剥离复合层涂料在大型铸钢件生产中的应用广西机电职工大学、广西机械工业学校(南宁530007)陈汝霞关键词:铸钢石英粉涂料锆英粉涂料铁橄榄石在铸型表面涂刷适当的涂料是提高铸钢件表面质量的重要措施之一,特别是对于大型铸钢件更是防止粘砂缺陷的主要措施。... 相似文献
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新研制的水基锆英粉涂料包括底涂料和面涂料。底涂料具有较好的涂渗性,涂渗深度达到2.6mm,它既有填隙作用,又可减缓砂型的激热膨胀,面涂料具有较好的厚涂性,单次刷涂的干厚度达到1.1mm,具有较好的抗金属液冲刷和侵蚀特点,新开发的Z-1砂是1种粒形圆整,表面光洁的铝硅系耐火材料,具有热膨胀率小,树脂耗量低和能适度烧结的特点,生产试验表明,配合使用上述Z-1砂和新型双层涂料,能有效防止呋喃树脂砂厚大铸钢件的金属渗透。 相似文献
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A multi-material hybrid patternless moulding process for complicated castings has been proposed. Moulding sands used in the hybrid moulding process include silica sand, ceramic sand, chromite sand, zircon sand, and steel shot sand. Experimental method was used to study the effects of moulding sands on the temperature field, mechanical properties, and dimensional precision of the iron castings. Under the condition that the wall thickness on different sides of the casting is the same, when the wall thickness is greater than 10 mm, the heat storage capacity of the moulding sands from strong to weak is steel shot sand, zircon sand, chromite sand, ceramic foundry sand, and silica sand. Tensile strength of the obtained castings from high to low is zircon sand, chromite sand, steel shot sand, ceramic sand, and silica sand. Contraction rate of the obtained castings from high to low is steel shot sand, zircon sand, chromite sand, silica sand, and ceramic sand. Therefore, steel shot sand and zircon sand can be used as chilled sand, and even can be used instead of cold iron when the casting wall thickness is greater than 10 mm. Zircon sand and chromite sand can be used to obtain high mechanical properties, and silica sand and ceramic sand can be selected to obtain high dimensional precision of the castings. Finally, a typical iron casting piece was tested by experiment using the hybrid moulding process. Excellent performances of iron castings confirm the feasibility of the hybrid moulding process. 相似文献
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新型铬铁矿粉铸钢复合涂料的研究与应用 总被引:1,自引:0,他引:1
介绍了新型铬铁矿粉水基和醇基铸钢复合涂料的组成结构、生产工艺、性能特点和应用实例.新型铬铁矿粉复合涂料生产成本仅约锆英粉涂料的二分之一,可代替价格昂贵的锆英粉涂料生产无粘砂、气孔等缺陷,表面光洁的合金钢和碳钢铸件. 相似文献
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铸钢件用醇基复合涂料的研究 总被引:1,自引:1,他引:0
为了解低锆英粉涂料成本,本文采用高铝矾土作辅助耐火材料,研制了醇基复合铸型涂料。试验表明,该涂料具有良好的复合烧结性,好的抗粘砂效果,易于涂刷且成本低,适用于碳钢及中小型合金风铸件。 相似文献
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对采用呋喃树脂自硬铬矿砂生产高铬不锈钢水轮机叶片铸件表面易出现"釉化"涂料层、界面型砂"釉化"烧结和粘砂缺陷进行了研究,并提出了解决措施.铸件粘砂的主要原因为钢液透过涂料层渗入铬矿砂,在界面发生氧化还原反应,将铬铁矿砂的铁还原出来,还原出的铁和砂粒形成致密混合物,并附着在铸件表面形成"釉化"烧结层.还原出的铁和铬渣以及砂粒中的未反应物,形成了致密的机械混合物,和铸件金属直接相连,附着在铸件的表面,形成粘砂.锆英粉涂料本身也和高铬钢发生微弱的化学反应.用新型添加剂及复合涂料改进型砂和替代锆英粉涂料,提高了钢液和铬矿砂界面涂料层的致密度、化学稳定性和耐火性,可以有效地解决这类问题. 相似文献
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AbstractThis investigation was carried out to identify the major factors and their degree of influence on the dimensional accuracy of spheroidal-graphite iron castings produced in chemically- bonded sand moulds. Test castings were poured into furan-resin-bonded zircon sand and silica sand moulds and sodium silicate/ CO2 bonded silica sand moulds. A comparison of casting sizes with those of the mould cavity into which they were poured showed considerable scatter and overlap. From these data the size that each casting would have had, had it solidified without graphite formation, was calculated and found to depend on mould cavity size for each type of mould. By isolating the differences in casting size due to graphite it was possible to identify the influencing factors. Thus castings poured into furan-resin-bonded zircon sand have the highest contraction and their size depends primarily on the amount of graphite present. The dimensions of castings poured into silica sand moulds show more variation and depend not only on the amount of graphite present and the structure of the metal but also on the thermal expansion of the silica sand moulds. 相似文献