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离心铸造气门座圈用高铬铸铁的组织及性能研究 总被引:2,自引:1,他引:1
根据气门座圈的生产和使用要求,研究了一种成分的离心铸造高铬铸铁铸态和回火态的组织和性能。结果表明,离心铸造的高铬铸铁其铸态组织由初生奥氏体、共晶奥氏体和共晶碳化物组成,回火态组织由回火马氏体、残余奥氏体和共晶碳化物组成;热处理后的高铬铸铁消除了内应力,减小了晶格畸变,具有较好的强度,并且有一定的硬度。离心铸造高铬铸铁气门座圈能满足大功率内燃机的使用要求。 相似文献
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湿型砂冷模法金属型离心铸管技术,是金属型在冷态下衬以湿型砂,在卧式离心铸造机上浇铸,以获得高延性管材的新技术。该技术不但可生产球墨铸铁上水管、燃气管,而且可以生产一般金属型离心铸造难以生产的双法兰、双承口等特种管型的管材。介绍了该技术的主要工艺和设备。 相似文献
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磨球是球磨机的磨料介质,常用的磨球主要有铸造磨球和锻造磨球两大类。铸造磨球按铸型工艺分为砂型铸造、金属型铸造、消失模铸造和离心铸造等。金属型铸造磨球具有组织致密等优点,但是用手工操作生产其劳动强度较大。因此,通过对金属型铸造磨球模具的改进,降低手工操作生产φ120mm磨球的劳动强度具有一定的实际意义。本文针对本公司手工操作生产φ120mm磨球的金属型铸造模具的实际情况,进行了上模模具的改进,降低了劳动强度。 相似文献
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卢宏 《特种铸造及有色合金》1997,(3):58-59
通过详细论述对比两种不同典型铸造工艺的实际生产现状、应用历史背景以及工艺特点分析,阐述了金属型重力铸造在相比低压铸造现代汽车工业多气门发动机铝缸盖这一关键复杂零部件的工业化铸造生产中所体现的全球性绝对发展优势。 相似文献
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应用PLC控制进行卧式滚筒离心铸造机的改进设计。根据离心铸造机的基本原理,在卧式离心铸造中其液体金属的自由表面是以位移旋转轴为轴线的圆柱面,规定金属液的密度大于异相质点颗粒的密度为正,反之为负,进行了单层金属型和双层金属型的主体结构设计,包括铸型端盖、端盖紧固装置、滚筒式离心铸型的滚道和定位、浇注系统等方面,给出了应用PLC控制的离心铸造机梯形图。 相似文献
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通过对高锰钢夹钩座铸造缺陷产生的原因进行分析并进行工艺改进,逐步消除了高锰钢夹钩座的铸造缺陷,提高了铸件的外观质量,同时,降低了材料消耗,减轻了铸件清理过程中的劳动强度,提高了生产效率。 相似文献
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《International Journal of Cast Metals Research》2013,26(5):314-326
AbstractSwirling casting is a process usually applied for the production of axial symmetric castings. The quality and performances of the products realised through this technology are widely influenced by the directionality of the produced solidification structure that rules the extension of the columnar zone. A correct design of the casting process is a fundamental issue to reach the desired properties featuring the final products, and to reach this goal, the coupling between the experimental observations and the computational simulations is needed. The work has also been integrated with finite element method analysis with the scope of evaluating the internal component behaviour (sphere, seat and support plate) of a sphere valve subjected to different load cases in order to understand whether the obtained microstructure of solidification is suitable and efficient for the construction of the valve. 相似文献
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支架是控制阀的关键部件之一.铸件的壁厚悬殊较大,铸造质量要求高,不允许铸件有较大的铸造缺陷.对控制阀支架铸件的铸造工艺进行了分析和实际试生产验证,确定采用平做竖浇工艺方案,较好地解决了铸件的疏松缺陷,生产的控制阀支架铸件达到X射线探伤四级以上的验收标准要求. 相似文献
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Y. S. Wang S. Narasimhan J. M. Larson S. K. Schaefer 《Journal of Materials Engineering and Performance》1998,7(1):53-65
A silicon-chromium alloy frequently used for heavy-duty diesel engine intake valves was tested against eight different insert
materials with a valve seat wear simulator. Wear resistance of these combinations was ranked. For each test, the valve seat
temperature was controlled at approximately 510 °C, the number of cycles was 864,000 (or 24 h), and the test load was 17,640
N. The combination of the silicon-chromium valve against a cast iron insert produced the least valve seat wear, whereas a
cobalt-base alloy insert produced the highest valve seat wear. In the overall valve seat recession ranking, however, the combination
of the silicon-chromium valve and an iron-base chromium-nickel alloy insert had the least total seat recession, whereas the
silicon-chromium valve against cobalt-base alloy, cast iron, and nickel-base alloy inserts had significant seat recession.
Hardness and microstructure compatibility of valve and insert materials are believed to be significant factors in reducing
valve and insert wear.
The test results indicate that the mechanisms of valve seat and insert wear are a complex combination of adhesion and plastic
deformation. Adhesion was confirmed by material transfer, while plastic deformation was verified by shear strain (or radial
flow) and abrasion. The oxide films formed during testing also played a significant role. They prevented direct metal-to-metal
contact and reduced the coefficient of friction on seat surfaces, thereby reducing adhesive and deformation-controlled wear. 相似文献
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目的 提高安全阀阀座与阀瓣的研磨维修质量和工作效率.方法 以砂纸为研磨介质,研究砂纸的细度、研磨压力、研磨机转速、研磨时间、研磨路径对阀座与阀瓣材料去除率与表面粗糙度的影响.通过正交实验,综合考虑各个工艺参数对材料去除率和表面粗糙度的影响,选择最佳工艺.结果 最佳工艺下,安全阀关闭件的材料去除率为26.2μm/min,表面粗糙度为0.028μm,研磨修复效率提高到90%.结论 研磨维修的最佳工艺为:砂纸目数1500目,研磨压力30 N,研磨机转速50 r/min,研磨时间20 min,研磨路径8字形. 相似文献
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