两种薄壁筒形件旋压工艺改进中的真空热处理试验

正为了提高原材料的利用率,对30CrMnSiA钢薄壁筒形件进行了旋压成形工艺改进。在试行旋压前对坯料调质、旋压后不淬火的工艺改进方案时,对坯料进行了真空调质处理的试验。在试行旋压后淬火的工艺改进方案时,又进行了薄壁筒形件旋压后的真空淬火、井式炉淬火等工艺试验。经过试验对比,最后以旋压后真空淬火的工艺方法,取得了工艺改进试验的成功。一、零件概况一种直径较大的薄壁筒形件如附图所示,材料为30CrMnSiA钢。要求力学性能满足抗拉强度Rm≥1080MPa,伸长率A≥10%。这种筒形件原先     

滚珠旋压成形工艺及研究现状

滚珠旋压技术作为旋压成形方法的一个分支,具有工艺方法简单、材料利用率高、产品成本低等优点,已成为国内外成形加工方法研究的热点。介绍了滚珠旋压成形工艺的原理、工艺参数及工艺特点,并对国内外研究现状进行了分析。     

大头套管成形工艺研究

针对该产品头部形状与尺寸同杆部相差较大的特点,采用无缝先镦头后旋压加工成形的工艺方案。解决了毛坯加工困难和提高材料利用率,生产出合格的制件。     

旋压成形带内筋筒形件的工艺研究及数值模拟

针对旋压成形带内筋筒形件的工艺进行试验研究和数值模拟.依据实际试件的尺寸及成形情况对边界、接触、摩擦以及空间运动等条件进行确定.建立三维有限元数学模型,分析在不同壁厚减薄率和旋轮进给率等工艺参数下内筋的成形情况和应力、应变及旋压力的变化规律.对试件在成形试验时出现的表面剥离、裂纹等缺陷进行预测和初步分析,可提高工作效率并降低研发成本,为进一步深入研究带内筋筒形件旋压工艺的成形机理和变形特点打下了良好基础,为优化工艺参数提供了有效方法和可靠依据.     

回归分析普通旋压筒形件的成形性

筒形件普通旋压中,制品常出现板材拉薄开裂和板材失稳起皱等成形性重缺陷。通过对铝合金材料筒形件普通旋压试验,发现板厚比t_0/d、旋压比D_0/d、旋轮移动速度V、旋压初角θ_0、旋轮移动距离p等多种加工参数对产品成形性影响很大。因此对生产实践和试验中获得的原始数据进行了计算机多重回归分析,得到了确保产品成形性的最适工艺参数。     

镍基高温合金筒形件毛坯错距旋压工艺研究

GH4169镍基高温合金筒形件流动旋压成形的难点是在大长径比、变壁厚的情况下保证内径精度。论述了该件流动旋压成形的工艺路线的制定、试验方法。在旋压过程中采用了错距旋压,探索了错距流动旋压的工艺参数对尺寸精度的影响,为该类产品的旋压成形提供了技术支持。     

房车转向节整体模锻关键技术与模具装置研发

房车转向节轮廊尺寸大、结构极其复杂,目前采用的分体制造技术存在材料利用率和生产效率低、产品性能差的问题。为此,提出了转向节整体模锻成形的工艺方案,着重研究了其关键工序弯曲成形的工艺优化并进行了专用模具装置开发。采用经典塑性成形理论、有限元数值模拟和试验相结合的方法,分析了弯曲过程的应力应变状态、金属流动和损伤分布。工艺试验结果表明,所提出方案合理,实现了以整体模锻取代分体制造,材料利用率由约45%提高至70%以上,生产效率提高4~5倍。     

多V型皮带轮旋压成形过程的有限元分析

基于动力显式有限元软件,以电磁离合器皮带轮为侧,开展了两个工序的旋压成形工艺的数值模拟,研究了旋压成形过程中材料变形情况,对成形件的应力应变分布进行了分析。模拟结果表明：采用旋压成形工艺,通过设置合理的进给量、芯模转速等参数,成形出的零件不仅形状和尺寸满足要求,而且芯模和旋轮所受载荷不大,旋轮最大载荷为540kN,芯模最大载荷为19kN。该研究对旋压带轮的非线性有限元分析和实际生产中设备的选择具有一定的参考和实用价值。     

气瓶坯料错距反旋成形的工艺研究

简述了气瓶坯料筒形件流动成形的工艺路线的制定、试验方法,旋压过程中采用反旋错距方法,探索了反旋错距流动旋压的工艺参数对尺寸精度的影响,为气瓶坯料旋压成形提供工艺支持。     

超半球壳体多道次拉深旋压工艺研究

针对1060超半球壳体基于板坯多道次拉深旋压进行成形性分析,提出两模法和两轮法的旋压成形试验方案,并设计不同旋压试验方案的芯模和旋轮工装.通过MC2000型数控录返旋压机,分别采用R13、R20和R25、R8不同圆角半径的圆弧式旋轮对1060板坯进行两模法和两轮法的多道次拉深旋压成形试验.两模法旋压毛坯件的凸缘边减薄严重,成形效果差;两轮法旋压采用R25旋轮4道次快速进给,R8旋轮4道次中低速精整旋压的旋压工艺,其旋压件贴模度高,成形效果好.试验结果表明:两轮法旋压工艺能实现板坯经多道次拉深旋压成形为超半球壳体.通过降低芯模转速,调整进给比和降低道次减薄率,可以消除旋压成形过程中出现的反挤、波纹和起皮等缺陷.     

装载机支撑轴新工艺的数值模拟及工艺改进

针对大型支撑轴的结构特点和工作环境,制定了合理的大型支撑轴成形新工艺,并采用有限元方法模拟和分析成形过程,比较了冲头形状对成形过程的影响。实践证明,对比现有的支撑轴加工工艺,零件的机械性能、材料利用率和生产率都有显著提高。     

密封套强力旋压成型工艺仿真过程研究

采用 simufact有限元软件进行数值计算,研究了某密封套的旋压成型工艺过程,得到了旋压过程中等效塑性应变及等效应力分布规律,分析了进给比对筒形件成型精度及旋压力的影响,即密封套旋压成型中间进程的等效塑性应变最大,进给比在一定范围内增大,壁厚偏差变大,成型质量变差。     

丁字臂锻造成形工艺改进及数值模拟

以汽车丁字臂零件为对象,分析了原有锻造工艺过程,根据金属塑性流动理论和设计方法,改进了丁字臂零件锻造成形工艺。采用有限元数值模拟软件对其改进后制坯工艺过程、金属填充状态进行模拟分析,同时对比分析了改进前后终锻等效应变分布和成形载荷。结果表明改进后的工艺提高了零件的材料利用率和模具寿命。模拟结果与实验结果吻合,对实际生产起到了指导作用。     

哈氏合金B3材料成形加工工艺方法

对哈氏合金B3材料的技术特性以及成形工艺进行了分析,并对哈氏合金B3材料封头成形工艺进行了试验。结果表明,采用模压或旋压的冷加工方法,封头成形质量完全满足设计要求,成形加工工艺简单、合理可行。     

金属薄壁筒体对轮旋压技术进展及应用探析

对轮旋压是成形大型高强金属薄壁筒体的关键技术。分别从塑变机理、成形精度影响与控制、组织演变与缺陷、对轮旋压设备等四方面概述了金属薄壁筒体对轮旋压技术的最新研究进展,指出时变非线性特点导致塑性流动控制困难是对轮旋压技术工程化应用的瓶颈。剖析了对轮旋压技术难点,分析探讨了其发展趋势,揭示出多源混动的对轮主动强力柔性旋压工艺对超高强金属、大尺寸薄壁筒体精密旋压成形的借鉴意义。     

NX项目冲压同步工程降成本控制研究

成本控制一直以来是冲压同步工程的重要内容。对白车身制造过程中冲压区域和车身焊接区域的成本进行了分析,以NX项目为例,冲压SE团队在模型设计阶段和产品工程化阶段通过对模型分缝线、断面分析、材料选择、整车材料利用率和生产制造成本等方面进行了仔细研究并进行相应成本控制,最后整车材料利用率达到62%以上,圆满完成既定目标。     

ANALYSIS OF MECHANICS IN BALL SPINNING OF THIN-WALLED TUBE

Ball spinning is applied to manufacturing thin-walled tube with high precision and high mechanical properties. On the basis of plastic mechanics, by simplifying ball spinning of thin-walled tube as plane strain problem, slab method is used for the purpose of calculating the contact deformation pressure. The spinning force components, the torsional moment, the deformation power and the deformation work are calculated further as well. The influence of the two important process parameters such as the feed ratio and the ball diameter on the spinning force components is analyzed in order to further control the spinning force components by regulating the two process variables during the ball spinning process. The stress and strain state in deformable zone as well as mechanics boundary conditions in ball spinning are obtained. The effect of the three spinning force components on the formability of the spun part is analyzed and validated through the ball spinning experiments. The theoretical and experimental results show that the radial spinning component plays a significant role in ball spinning of thin-walled tube, and the mechanics situation in backward ball spinning contributes to enhancing the plasticity of the metal material, but that in forward ball spinning contributes to advancing the axial flow of the metal material.     

A study of the spinning force of hollow parts with triangular cross sections

The noncircular spinning is one of the recent breakthroughs of the traditional spinning processes. The spinning force is one of the important parameters for designing the spinning equipment and one of the main factors influencing the forming quality of spun parts. The variation of spinning force during noncircular spinning is considerably different from that of the conventional spinning due to the high-speed reciprocating movement of the roller induced by the variable spun workpiece profile. This paper presents an experimental investigation of spinning force characteristics of a hollow part with triangular cross sections using an octagon ring transducer based on electrical measuring method. A series of experiments using profiling driving spinning method was carried out to study the effects of the main process parameters, such as the roller feed rate, blank thickness–diameter ratio, and mandrel rotational speed, on the spinning force characteristics. The important characteristics of the force components of noncircular spinning were discussed based on the electrical measuring results. Furthermore, the variations of force components were compared with those obtained in the cases of conventional spinning and 3D non-axisymmetrical spinning. The results show that different from the conventional spinning and similar to the 3D non-axisymmetrical spinning, the three components of spinning force along the axial, radial, and tangential direction of roller vary periodically with the mandrel rotational angle. Different from the conventional and the 3D non-axisymmetrical spinning, the maximum spinning force is related to the mandrel rotational speed, even if the feed rate of roller remains constant, and increases with the increase of the mandrel rotational speed.     

Study on compound spinning technology of large thin-walled parts with ring inner ribs and curvilinear generatrix

Given their rapid development, aerospace and other high-tech industries are in urgent need of process technology for large complex thin-walled shells represented by large thin-walled parts with ring inner ribs and curvilinear generatrix. To make up for the deficiency in existing forming methods, this paper presents a compound spinning process that integrates counter-roller spinning, multi-neck spinning, and hot spinning. The finite element models for the counter-roller spinning and multi-neck spinning forming of such parts are established, and these models can simulate the influences of different spinning process parameters on workpiece maximum equivalent stress and maximum ovality. The 2A12 aluminum alloy tube blank is used in this paper. The process parameters for obtaining the counter-roller spinning for such parts are as follows: a feed ratio of 1.0 mm/r and a roller nose radius of 8 mm. The process parameters of multi-neck spinning are as follows: a feed ratio of 3.0 mm/r and a roller nose radius of 80 mm; and the forming temperature of hot spinning is 200–250 °C. Verification by a compound spinning test found that the numerical simulation results are consistent with the process test results. The process parameters can be used for guiding the actual production of large thin-walled parts with ring inner ribs and curvilinear generatrix.     

镁合金轮毂等温挤旋成型装置的研究

通过设计挤旋成型装置,实现了镁合金轿车轮毂等温挤旋成型工艺,提高成形效率与加工精度。以有限元理论为依据,对汽车轮毂挤旋成型工艺特点进行分析,建立了符合实际要求的力学模型。采用四节点四边形单元对毛坯进行网格划分,然后对挤旋成形过程起关键作用的工艺参数:加工温度、挤旋轮半径、进给比、主轴转速进行了正交试验的数值模拟,利用方差分析各因素对指标的影响大小,优化各个工艺参数之间的配合。结果表明成型工艺可行,设计的装置具有一定价值。