圆锥轴承内圈锻件反挤压辗扩工艺的研究应用

分析圆锥轴承内圈锻件反挤压成形辗扩工艺的特点,通过与正挤压封闭式成形工艺比较,得出该工艺具有减小设备负荷、加大设备生产能力、扩大设备加工范围、减小料芯积压等优点。根据我厂情况,采用反挤压成形辗扩工艺替换正挤压封闭式成形工艺后,在提高了材料利用率、降低了损耗的同时也改善了锻件纤维组织流向,延长了轴承使用寿命。     

铝合金轮毂等温挤压工艺与模具设计

分析铝合金轮毂的等温挤压成形工艺和成形关键，制定了相应的工艺路线及有效的解决方案，并介绍了相关挤压模设计，通过试验成功验证了该零件挤压成形的可行性，为该类零件的挤压成形开辟了新的道路。     

微挤压成形工艺仿真建模与分析

微细成形是一种绿色、节能的新型加工方法，但是由于微细成形的特殊加工条件和状态，传统的加工方法已经不能直接应用到该领域。针对重要的微挤压成形工艺特点，分析了特征尺度效应和晶粒尺度效应对微挤压材料成形性能的影响，引入尺度效应影响的刚塑性材料本构模型，利用ABAQUS／Explicit软件建立FEM（finite elementmethod）模型对微细挤压工艺进行了数值分析。通过工艺仿真分析，揭示了各工艺参数对微细挤压工艺的影响，为微细挤压工艺设计与相应的模具设计提供了可靠的理论指导。     

高强度铝合金管材热挤压工艺及力学性能分析

分析了高强度铝合金(7075铝合金)管材热挤压成形变形特点,对高强度铝合金(7075铝合金)管材热挤压成形进行了工艺实验研究。确定了热管材挤压成形工艺参数,分析了热管材挤压成形时挤压力变化规律,分析了变形程度对挤压后管材机械性能的影响规律。研究结果发现,7075铝合金管材热挤压成形时必须严格控制坯料温度、模具预热温度、润滑方式、挤压速度、挤压比等工艺参数。     

计算机仿真技术在挤压成形工艺上的应用研究

利用计算机仿真技术研究了薄壁壳体件挤压成形工艺的优化设计方法。首先,建立三维模型,通过对模型特点的分析确定了挤压成形方法;然后利用有限元软件对挤压成形工艺参数进行模拟仿真分析;最后,通过对仿真模拟参数的综合分析并参考实际工程需求,确立了合理的挤压成形工艺参数。     

长轴类花键挤压成形极限研究

建立了长轴类花键无约束正挤压的力学条件，采用等挤压比流动模型对矩形花键挤压进行了上限分析，讨论了变形程度、凹模型腔尺寸、齿形参数、摩擦因子等对无约束正挤压挤压相对应力及成形极限的影响，给出了花键挤压相对应力的经验公式，为正确制定挤压工艺提供了理论依据。     

小型轴承套圈温挤压工艺及模具设计

以6203轴承套圈为例,通过对套圈的温挤压成形工艺过程、成形性能及工艺设计进行理论分析和设计计算,完成了锻件毛坯尺寸、温挤压成形凸模和预应力组合凹模的设计。基于DEFORM体积塑性成形软件,模拟了轴承套圈温挤压的成形过程,并对变形速度、成形性能、成形质量和温挤压应力进行了分析计算。     

7075铝合金杯形反挤压成形计算机仿真

基于DEFORM-3D仿真软件,分析了7075铝合金带筋杯形件反挤压成形过程,研究了挤压速度、扭转速度、坯料初始温度对成形过程的影响,通过正交试验获得最佳成形工艺参数,并将传统的挤压成形与扭转挤压成形进行对比。结果表明,在传统反挤压的基础上,扭转作用使得坯料成形所需载荷降低,金属内部等效应变分布更均匀,通过正交试验最终得到了优化后的成形工艺参数,为铝合金杯形件反挤压成形提供理论基础。     

法兰轴零件的冷挤镦成形工艺及模具设计

结合冷挤镦工艺的成形特点,对法兰轴零件进行冷挤镦工艺分析,计算毛坯尺寸及冷挤压镦力,并根据DEFORM软件模拟计算对法兰轴成形工艺进行优化。成形模具分为两步正挤压、一步反挤压与镦粗复合,凹模均采用三层预应力组合形式的凹模,凸模尾部锥面即可保证凹凸模的精准对中,又可保证成形零件的表面及内部质量。     

自润滑关节轴承精密挤压合套技术

针对挤压合套自润滑关节轴承结构特点,分析对自润滑层无损伤的挤压合套精密成形工艺的关键技术。通过数字化精密塑性成形技术,对成形工艺过程进行数值模拟,分析影响自润滑层性能的成形应力分布、球面接触面积及残余应力。数值模拟方法可以优化成形工艺参数与成形方法,最大限度地减少挤压合套过程对自润滑层的损伤,保证得到合理均匀的游隙,从而提高产品使用寿命与性能。     

2Cr13不锈钢温挤压工艺探讨

2Cr13钢是一种马氏体不锈钢。退火后硬度较高。冷挤压很困难。介绍通过选择合理的温挤压工艺参数，研制高效的温挤压涂料等，成功地获得了良好的挤压件方法。     

双相不锈钢制冷凝器SAF2507换热管与316L管板的焊接工艺

塔顶冷凝冷却系统是炼油厂腐蚀最严重的部位，寻求新材料代替碳钢、高合金钢等腐蚀比较严重的材料，是工程应用的需求。文章介绍了双相不锈钢焊接的特点，提出了双相不锈钢制冷凝器SAF2507换热管与316L板焊接工艺，采用不同接头形式、不同的焊接保护气体进行了焊接试验，并通过对焊缝及热影响区组织的金相分析，找出了合理的焊接工艺。     

An analysis of the nosing process of metal tubes

In this paper, the finite element method is used to investigate the cold nosing process of partially laterally constrained metal tubes with a conical die from a tube billet. A series of simulations on the tube nosing using the FEM program ANSYS/LS-DYNA was carried out. The influences of the process parameters such as tube length, tube thickness, die fillet radius, die angle, friction factor, strength coefficient and strain hardening exponent of the billet material on the critical nosing ratio of the tube are analysed. Experiments were carried out with stainless steel SUS304 tube billets at room temperature, and the results of experiments were compared with the FEM calculations.     

A study of process and die design for ball valve forming from stainless steel tube

In this paper, two process and die design methods for ball valve forming from stainless steel tubes are compared: one is the tube hydroforming method (THFM), and the other is the tube nosing method (TNSM). Simulations on hydraulic expansion, axial feeding, and tube nosing of the ball shell forming with the two methods using the program DEFORM-3D are carried out. The influence of the two methods on workpiece formability and wall thickness distribution of ball valve forming is examined. A tube nosing experiment is carried out with a SUS304 stainless steel tube at room temperature. An accepted product of ball valve satisfying the industrial demand is obtained using TNSM.     

Portholes-equal channel angular pressing: novel technique for extrusion of 6061 aluminum alloy tube by subsize billet

Wrought 6061 Al alloy exhibits the prospective applications in the form of tube extrusions. In this study, billets of 6061 Al alloy were extruded under optimized conditions by a novel technique namely portholes-equal channel angular pressing (P-ECAP) extrusion. This technique is different from the conventional extrusion as the dimension of the product is greater than that of the billet. The extruded tube produced by the method was characterized for their microstructure as well as for their physical and mechanical properties. The tube that was fabricated using P-ECAP die showed significant refinement in microstructure with improved mechanical properties outside the seam joint portion. However, the extrusion loads using porthole die were less compared to that in the conventional method by using columniform billet because of the decrease in billet dimension or extrusion ratio. Furthermore, microstructure at seam joints of 6061 Al alloy extrusion was discussed in detail in this study. Thus, the P-ECAP technique has significant potential for substantial energy saving.     

温度和摩擦条件对不锈钢管材挤压过程的影响

以316LN不锈钢管材挤压件为例,采用3种温度状态和4种摩擦因子的不同组合共进行12组挤压过程的数值模拟,得到了不同参数下坯料温变、模具载荷及材料流动情况,掌握了温度和摩擦条件对挤压力和材料流动的影响规律,为管材挤压工艺优化提供了理论依据。     

弹体温成形工艺改进的研究

针对弹体温成形实际生产过程中模具寿命低及壁厚差大的问题,通过对温成形工艺参数的分析,提出弹体温成形过程的改进方案,即在温挤压工步之前增加预成形工步,在温挤压工步之后增加变薄拉深工步.经对改进工艺的计算机模拟及实验验证表明,此改进的工艺能够减小壁厚差,降低凸模温升,延长凸模寿命.     

A Study on the Extrusion by a two-step process for manufacturing helical gear

Much research has been carried out in the manufacturing of helical gears by cold forging or by extrusion. Although cold forging is applied to some bevel, spur, and helical gears, problems in connection with the reduction forming load and tool life still make it difficult for these methods to be commercialized. In this study, focusing on reducing a load in forming helical gears, the extrusion of helical gears by two-step process is proposed. This process is composed primarily of extruding a billet to a spur gear and then twisting the previous spur gear extruded to a helical gear. Cylindrical billets of Cr-Mo steel(SCM 415) and aluminium alloy(Al60 series) were used as specimen materials for the experiments. The maximum loads obtained by upper-bound analysis and FEM are compared with the results of experiments. The loads of the analysis have good agreements with those of the experiment. The newly proposed method can be used as an advanced technique that remarkably reduces the forming load and replaces the conventional forming.     

316L不锈钢管手工钨极氩弧焊焊接工艺

通过对316L不锈钢焊接性能的分析、手工钨极氩弧焊焊接过程的控制、焊后进行无损检测、晶间腐蚀、力学性能等项目的数据分析,焊接接头的机械性能和耐腐蚀性达到了工艺要求,保证了316L不锈钢管的焊接质量,为广大焊接工作者提供参考。     

微小尺寸等壁厚不锈钢螺旋管充液压制成形方法研究

为了解决常规螺杆钻具寿命短与微小尺寸螺杆钻具等壁厚定子难加工的问题,本文采用充液压制成形工艺加工微小尺寸等壁厚螺旋管,基于304不锈钢拉伸实验,建立了充液压制成形等壁厚螺旋管有限元模型,用数值模拟方法研究管件外径、壁厚、液压力大小、液压力加载路径、压制速度、摩擦系数对螺旋管质量的影响。结果表明,管件外径为51.8 mm,壁厚为5.3 mm时,螺旋管质量较好,最大液压力为650 MPa,液压力加载路径为路径5,模具挤压速度为0.429 m/s,摩擦因数不超过0.125时,螺旋管加工质量较好,导程误差近似为0,壁厚误差小于8%,平均厚度为5 mm,螺旋管中部壁厚误差小于3%。研究结果可为生产实际中微小尺寸等壁厚不锈钢螺旋管的成形工艺提供参考。