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火车车轮成形工艺研究及有限元模拟 总被引:8,自引:2,他引:8
介绍了火车车轮的成形工艺。采用有限元模拟了车轮成形工艺的镦粗和预成形工步,得出变形过程中材料的流动规律、工件内部的应变场和温度场等信息。通过多次模拟镦粗压下量对预成形的影响,确定了最佳的镦粗压下量。这些信息为变形过程的控制提供了理论依据。 相似文献
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轴类件局部成形是节材、高效的精密塑性成形新工艺。在细长杆形坯料的局部成形工艺技术中,顶镦工艺应用最为广泛。当锻件变形长径比ψ>2.5时,通过一次顶镦工步完成将产生折叠,需要多次顶镦工步完成工件的成形。基于此,文章提出采用将自由镦粗、挤压、闭式模锻工艺相结合的轴类件局部成形新工艺——浮动模局部成形工艺,可避免细长杆局部镦粗工艺中的弯曲折叠,并减少成形件表面的拉应力。采用浮动模局部成形工艺可实现细长杆坯料变形长径比ψ>4的一次成形,解决了现有工艺中的一系列难题,为细长杆坯料局部精密成形提供了新的途径。 相似文献
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数值模拟技术在火车轮热成形工艺设计中的应用 总被引:2,自引:2,他引:0
通过采用体积成形有限元模拟软件DEFORM-3D对火车轮热成形的镦粗、预成形、压弯工艺进行有限元数值模拟与分析,阐述了DEFORM-3D数值模拟技术在火车轮热成形工艺设计中对确定最佳镦粗高度、轮坯轧制变形量、选用合理镦粗模具、预测压弯成形变形最大部位、分析车轮缺陷与坯料缺陷之间的关系等方面的有效应用.这对车轮热成形工艺的合理设计、提升车轮成形质量控制水平、提高生产效率、减低生产成本都具有重要的意义. 相似文献
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镦挤拔模斜度对成形的影响规律研究 总被引:3,自引:0,他引:3
由于坯料在镦挤变形过程中要经过镦粗和挤压变形,给模具参数的选择带来一定的难度。凹模的拔模斜度是影响成形工艺的一个重要参数,关于拔模斜度大小的选取,目前尚无准确的公式、曲线或表格。论文以数值仿真技术为依托,建立了基于刚粘塑性有限元法的镦挤热成形工艺有限元模拟模型,利用塑性成形仿真软件DEFORM-3D对镦挤工艺进行模拟仿真,分析讨论了不同拔模斜度对镦挤热成形过程的影响以及成形过程中可能产生的缺陷,建立了基于数值模拟仿真模拟结果的最佳拔模斜度成形规律曲线,为指导镦挤工艺设计中凹模拔模斜度的选择提供了理论依据,也为其它挤压凹模斜度的选择提供了参考。 相似文献
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采用数值模拟的方法分析单道次纯钨闭塞式双通道等径角挤压工艺的变形特点,并对比等径角挤压工艺和双通道等径角挤压工艺经过Bc路径4道次变形后的应变积累和分布特点。同时,为验证有限元模拟的准确性,开展了物理实验。结果表明,闭塞式双通道等径角挤压变形过程可分为初始阶段、镦粗成形阶段、剪切变形阶段和最终成形阶段。3种工艺经4道次变形后均发生较大的应变积累,但是由于闭式模膛对试样头部的镦粗作用,闭塞式双通道等径角挤压经过4道次变形后等效应变量最大,且等效应变分布最均匀。通过对模具应力的分析,闭塞式双通道等径角挤压和双通道等径角挤压工艺可以有效解决等径角挤压工艺冲头偏载问题,且试样经闭塞式双通道等径角挤压变形后具有较大的静水压力,提高了纯钨塑性,有利于进行多道次变形。闭塞式双通道等径角挤压工艺变形后的试样可分为4个区域:剪切变形区、伸长变形区、头部小变形区和尾部未变形区。 相似文献
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我国不锈钢管生产的现状 总被引:2,自引:1,他引:1
简介了1995年以来我国不锈钢的产量、进口量、消耗量以及钢管的产量、生产工艺和装备情况及存在的问题。指出国内不锈钢管市场有着巨大的潜力。认为我国不锈钢无缝管与焊管的比例为45:55较合适。 相似文献
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A. El-Domiaty 《Journal of Materials Engineering and Performance》1997,6(4):481-495
The curling of thin tubes under compressive loads produces double walled tubes for many engineering applications. Experiments
have been performed on annealed copper, low carbon steel, stainless steel, and aluminum tubes to determine the relationship
between the curling process parameters and the tube geometry, as well as tube material properties. Effects of friction and
work hardening during forming are included in the analysis. The analytical and experimental results are compared with published
results to determine the validity of the proposed analytical model.
The model can be used to determine the curling load and the correct die radius for successful curling. For simple and quick
determination of the die radius, the present work introduces design curves, which correlate the tube geometry with the radius
of the forming die. 相似文献
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叙述了锂鱼钳塑性变形的工艺分析、设计辊锻件图、计算毛坯截面图及直径图、确定辊锻道次、选择毛坯尺寸、各道工序变形量的分配及计算各道辊锻的毛坯尺寸。介绍了锂鱼钳制坯一成形辊锻工艺的产生过程。阐明了采用多道连续辊锻工艺代替传统旧工艺的优点。 相似文献
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无缝钢管生产技术的新进展 总被引:8,自引:0,他引:8
无缝钢管生产已逐渐从追求产量向提高质量,扩大品种,降低成本方向发展,其间不断涌现新的设备与工艺。简介了国内外生产技术的发展情况;比较了步进式与环形式管坯加热炉的应用特点;概述了锥形辊穿孔机、少机架限动芯棒连轧管机、PQF连轧管机及半浮/在线脱棒技术、紧凑式轧管技术、张力减径机/定径机的三辊可调技术及快速换辊技术、钢管质量自动控制技术(如连轧管机的HGC控制技术、张力减径机增厚端及壁厚自动控制技术)、钢管在线壁厚检测技术等新工艺、新设备的特征。 相似文献
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C. Yang T. WenL.T. Liu S. ZhangH. Wang 《Journal of Materials Processing Technology》2014,214(11):2461-2467
Extending incremental forming technology into the production of tubular parts has promising prospects; however, fundamental rules of the approach have not yet been fully revealed and knowledge on the technology is lacking. This paper is focused on the dieless incremental hole-flanging of thin-walled tube for producing branched tubing. 316L stainless steel tubes with an outer diameter of 38 mm and thickness of 0.5 mm were used for the experiment and numerical simulations. Considering the uncertainty of initial curl direction of the tube wall at the extrados, where buckling is also prone to occur due to the excessive axial pressure during the forming course, an improved bar tool with a conical surface was proposed. Estimation of the precut hole size and processing route planning were discussed based on the designed branching. Force and deformation behavior along with the defects in the process, which are quite different from those in conventional incremental sheet forming, were summarized. The results prove that it is feasible to produce specific tubular parts by means of incremental forming with obvious flexibility, agility, and expandability. 相似文献
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To fabricate a probe needle, a tubular cathode was applied by electrochemical etching. A tungsten wire was used as an anode,
and a stainless steel tube was used as a cathode, respectively. The stainless steel tube was partially immersed into a sodium
hydroxide solution. After the tungsten wire was aligned at the center of the stainless steel tube, electricity was supplied
from an external power source. During the experiment, the level of solution that was inside the stainless steel tube rose
higher than that of the outer solution of the stainless steel tube, due to bubbles generated on the inner surface of the stainless
steel tube, and the inner solution increased in volume. Using this process, the length of the probe needle tapering could
be controlled without using a vertical loading system or controller. 相似文献
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针对核电站乏燃料不锈钢水池6 mm厚的304L不锈钢板材,采用高效双钨极氩弧焊工艺焊接试板,对双钨极氩弧焊接头进行拉伸性能、冲击性能、弯曲性能、硬度、金相组织、铁素体含量、抗晶间腐蚀性能及粗晶区晶粒度评级等试验研究. 结果表明,采用双钨极氩弧焊焊接核级304L不锈钢材料,焊接接头综合性能良好;双热源的工艺虽然增加了热量,但金相组织仍为奥氏体和少量铁素体的典型形貌,铁素体含量在5% ~ 12%范围内,同时焊接接头粗晶区未发现明显的粗化现象,具备一定的抗热裂性能且保持了良好的塑韧性;晶间腐蚀试验未发现接头有敏化现象,表明该焊接接头耐腐蚀性能优良. 综上试验说明核电站不锈钢水池双钨极氩弧焊接头综合性能可靠. 相似文献
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在分析铝合金R形凹槽方管及其生产工艺的基础上,指出现有焊管成型工艺无论是圆成方或直接成方在变形凹槽类管形方面都存在不足。提出在融合冷轧型钢工艺与焊管成型工艺的基础上,先将钢带轧制并焊接成R形凹槽圆管,然后再变形为R形凹槽方管的新思路。针对凹槽类焊管提出了同时轧制、一次轧制等"一轧定终身"的设计原则、设计方法和品质评判标准。成功试制出视觉效果与铝合金R形凹槽方管样品相媲美的R形凹槽方钢管,使金属家具制造企业在材料选用、成本控制方面多了一项选择。 相似文献