共查询到20条相似文献,搜索用时 734 毫秒
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本文对冷床上卸钢液压系统存在的问题进行了分析,找出了产生问题的原因,并对原液压系统进行了改造,减少了油液的泄漏,提高了系统的稳定性,减小了维修强度,降低了维修成本,提高了系统的工作效率。 相似文献
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分析了望远镜镜身的结构,提出了塑件成型及模具设计的关键点,设计了模具的整体结构。设计了可相对运动的组合式型芯,以增加内抽芯机构的运动空间,通过塑件推出时带动螺纹滑块的移动实现了内侧抽芯。设计了矩形型芯镶块、加工了避空结构,采用螺钉固定,解决了狭小空间安装小型芯的问题,避免了模具干涉。采用了锥面配合,提高了模具的定位精度,减小了配合件的摩擦。经生产验证,该模具生产的塑件质量满足图纸要求。 相似文献
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本文通过生产实践,提出了拖拉机变速箱体产生裂纹的原因是内应力超过了抗拉强度所致。采用型内孕育,改善了铸件的组织结构,提高了抗拉强度,抵消了冷却不均匀所产生的内应力,消除了裂纹,提高了经济效益。 相似文献
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《锻压装备与制造技术》1977,(1)
我厂锻工车间的六台余热锅炉安装了自动给水装置,实现了远距离集中控制,避免了干锅和满锅的不安全因素,提高了锅炉效率,减轻了工人的劳动强度,改善了劳动环境,节省了劳动力,原分散管理需24人,现集中管理仅需5人。 相似文献
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为加大拖拉机导向轮合件的生产规模, 开发研制了一台自动焊专机, 实现了拖拉机导向轮合件的全自动焊接, 提高了劳动生产率, 满足了规模生产的需求; 还实现了该零件的自动焊接工艺参数的一元化控制, 减小了人为因素对产品质量的影响, 保证了产品的质量, 减轻了工人的劳动强度, 降低了生产成本。 相似文献
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E. D. Pleshka 《Surface Engineering and Applied Electrochemistry》2008,44(2):92-97
The iron-plating process in methyl sulfate chloride electrolytes was investigated. The conditions of iron plating ensuring the coating adherence with steel and pig iron required in the technological processes of reconditioning and strengthening of machine pieces are determined. Process conditions ensuring the high coating adherence with steels 45, 15HGT, 40H, and grey and high-strength pig iron are found; they include steps: powering on of the polarizing current with the initial density of 0.15–0.5 kA/m2 immediately after insertion of pieces in the electrolyte and raising of the current density up to the working level with a rate of 4–5 A/m2 s. Metallographic, polarizing, and other research show the influence of the initial electrolysis conditions on the formation of the first layers of coverings and the process of iron electrocrystallization on structural phases of tempered steel and grey and high-strength pig iron. 相似文献
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Although compacted graphite iron has been known for more than four decades, the absence of a reliable mass-production technique has resulted in relatively little effort to exploit its operational benefits. However, a proven on-line process control technology developed by SinterCast allows for series production of complex components in high-quality CGI. The improved mechanical properties of compacted graphite iron relative to conventional gray iron allow for substantial weight reduction in gasoline and diesel engines or substantial increases in horsepower, or an optimal combination of both. Concurrent with these primary benefits, CGI also provides significant emissions and fuel efficiency benefits allowing automakers to meet legislated performance standards. The operational and environmental benefits of compacted graphite iron together with its low cost and recyclability reinforce cast iron as a prime engineering material for the future. 相似文献
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Uma Batra S. Ray S. R. Prabhakar 《Journal of Materials Engineering and Performance》2003,12(4):426-429
The variation in the austempered microstructure, the volume fraction of retained austenite, Xλ, the average carbon content of retained austenite, Cλ, their product XλCλ and the size of bainitic ferrite needles with austempering temperature for 0.6% Cu alloyed ductile iron have been investigated
for three austempering temperatures of 270, 330, and 380 °C for 60 min at each temperature after austenitization at 850 °C
for 120 min. The austempering temperature not only affects the morphology of bainitic ferrite but also that of retained austenite.
There is an increase in the amount of retained austenite, its carbon content, and size of bainitic ferrite needles with the
rise in austempering temperature. The influence of austempering time on the structure has been studied on the samples austempered
at 330 °C. The increase in the austempering time increases the amount of retained austenite and its carbon content, which
ultimately reaches a plateau. 相似文献
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我公司在阀门安装过程中,由于紧固时用力不均,导致与循环冷水泵出口相连的Dg500 PN1.6单向铸铁阀门的出口法兰根部沿周向出现裂纹,经检查发现裂纹长度有圆周长度的三分之二还多,裂纹深度基本上是贯穿性的,部分裂到法兰密封面上(图1中粗黑线),还有部分裂穿法兰螺栓孔之间(图1中虚黑线).针对 相似文献
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G. Hinojosa P. S. Schabes-Retchkiman J. Oseguera 《Journal of Materials Engineering and Performance》1998,7(3):312-316
A study of nitride-phase formation in alloys nitrided by glow discharge plasma nitriding was performed by high-resolution
electron microscopy. The iron and steel samples were nitrided above and below the eutectoid transformation point (590 ‡C).
After nitriding, the samples were annealed for several treatment times at 400 ‡C. The microstructure and identification of
the iron nitrided phases formed by nitriding and annealing were investigated by x-ray diffraction (XRD), optical microscopy
(OM) and mainly high resolution electron microscopy (HREM) in a JEOL-4000EX high resolution microscope at 400 kV. The results
of the characterization show a surface ε compact nitride layer, which is transformed into ε + γ during cooling. The tempering
process affects the surface hardness of the samples. After an initial increase relative to the untreated sample, the microhardness
diminishes after long treatment times. This behavior is correlated with the αt’’ phase appearance, growth, and transformation. 相似文献
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