共查询到17条相似文献,搜索用时 375 毫秒
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球形内模扩径减壁冷拔新工艺是为提高模具寿命、加大变形量、改善冷拔操作条件而试验的一种新的工艺技术。其变形过程如图1所示。和传统的短芯棒冷拔管方式不同,该工艺采用处于游动状态的球形内模,取消了内模固定装置,整个变形过程包括减径一扩径一减壁一减径等几个阶段。通过工厂试验和小批量试生产证明该工艺具有‘定技术价值,是我国冷拔钢管的一项工艺革新。198工年第10期一分「—}\ 图!变形过程图示 l一球形内模;2一外模,3一钢管 1.试验条件及主要结果 试验在15t冷拔机上进行,拔制速度为18m/nlin。试验采川「艺参数如下: 毛管规格:功74 … 相似文献
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新型Mn-Cr齿轮钢的动态再结晶行为研究 总被引:1,自引:0,他引:1
采用Gleeble1500热模拟试验机研究了变形温度、变形速率、变形程度及奥氏体晶粒尺寸对新型Mn-Cr齿轮钢动态再结晶行为的影响。确定了该Mn-Cr齿轮钢的动态再结晶激活能Q及应力指数n分别为378.6kJ/mol和5.81,在热轧齿轮钢管穿孔工序中,变形温度为1100-1150℃,变形量为40%~54%,奥氏体处于动态再结晶状态;而在轧管及减径工序中,变形温度分别为1000~1050℃和900-950℃,变形量分别为21%和31%,奥氏体均处于加工硬化状态。 相似文献
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用传统方法进行张力减径机孔型设计时是以减径率为依据分配变形量。由于该方法没有充分考虑钢管壁厚的影响,致使成品管质量和乳机工作状态受到不利影响。作者阐述了一种沿机架分配钢管变形量的新方法——基于延伸率的分配方法,并给出了设计实例。采用这种设计方法后,钢管在各机架的变形量更加均匀,轧机工作状态也更为稳定。 相似文献
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为了实现无缝钢管生产工艺流程中定(减)径之后矫直之前的控制冷却,采用数值模拟方法研究了20号钢管轧后冷却过程的组织力学性能变化规律。首先采用试验方法测定钢探头在不同冷却介质条件下的温度变化曲线,根据反传热法基本原理计算得出钢探头冷却过程中表面换热系数与工件温度的关系。然后,采用有限差分法建立了钢管冷却过程中的温度场、组织相变及力能性能预测系统,分析了不同冷却工艺条件下钢管的组织状态与力学性能。最后,进行钢管空冷过程的试验分析,测定了不同时刻的温度数据和冷态钢管的力学性能,其计算结果与实测数据吻合良好。该研究结果可为实现无缝钢管控制冷却提供基础性数据。 相似文献
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According to the theories for stretch reducing process and steel tube plastic deformation, the energy method was used to mesh the rolled deformation zone of the steel tube into the upper limit elements, and an admissible velocity field was constructed to deduce a series of formulas of the inner virtual power consumption of deformed bodies. The roiling force during the stretch reducing process could be obtained by optimizing the upper limit power, which could provide guidelines for a proper choice of the stretch reducing process and devices for steel tube companies, as well as new products and devices. 相似文献
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Numerical Simulation of Continuous Tension Leveling Process of Thin Strip Steel and Its Application 总被引:1,自引:0,他引:1
Cold rolled thin strip steel of high flatness quality undergoes multistage deformation during tension leveling. Thus, the parameters of set up and manipulating are more difficult. With the aid of FE code MSCMARC, the tension leveling process of thin strip steel was numerically simulated. Concentrating on the influence of the roll intermeshes in 2# anti cambering on the distribution and magnitude of residual stresses in leveled strip steel, several experiments were done with the tension leveler based on the results from the simulation. It was found from the simulation that the magnitude of longitudinal residual stresses in the cross section of the leveled strip steel regularly presents obvious interdependence with the roll intermeshes in 2# anti cambering. In addition, there is a steady zone as the longitudinal residual stresses of the surface layers in leveled strip steel vary with the roll intermeshes of 2# anti cambering, which is of importance in the manipulation of tension levelers. It was also found that the distribution of strains and stresses across the width of strip steel is uneven during leveling or after removing the tension loaded upon the strip, from which it was found that 3D simulation could not be replaced by 2D analysis because 2D analysis in this case cannot represent the physical behavior of strip steel deformation during tension leveling. 相似文献
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为了进一步降低高牌号无取向硅钢制造成本,通过优化热变形工艺,促进动态再结晶,实现不常化"一次冷轧"法生产低成本高牌号硅钢成为一种可能。实验室以2.5%(Si+Al)硅钢为基,为尽可能地接近实际粗轧情况,通过Gleeble-1500D热模拟试验机以0.1s-1 恒应变速率对加热温度1100~1200℃,热变形温度900~1050℃,变形量20%~65%,进行模拟。通过显微组织的观察,结果表明:在恒变形速率下,原始组织为等轴晶、热变形温度越高、变形量越大则越有利于动态再结晶的发生,而加热温度(≤1200℃)对动态再结晶无显著影响。 相似文献
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为了研究推/张力(0~15 MPa)对不锈钢(Cr18Ni8,2 mm壁厚管)/碳钢(0.06%~0.12%C,Φ16 mm,圆棒)复合钢筋轧制过程的影响,应用有限元软件Msc.Marc建立了复合钢筋轧制过程的有限元模型。通过模拟考察了推/张力对不锈钢/碳钢复合钢筋的宽展变形,结合面的接触应力和不锈钢圆周壁厚的影响,重点通过实验考察了推力轧制对两金属结合强度的影响。结果表明,施加张力后轧件宽展量减小,而施加推力后其值增加;不锈钢壳与碳钢芯间的接触应力随推力的增加、张力的降低而增大。推力轧制有利于两金属的复合,可以提高复合不锈钢和碳钢芯的结合强度。 相似文献
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Based on the deformation characteristics of Y-type mill, this paper proposes a finite element model for dynamically simulating the formation process of shaped steel tube for driving shaft. The distributions of stress and strain were obtained from the simulation. The outer diameter and transverse wall thickness were also analyzed quantitatively. Experiment was done on Y-type mill. A comparison between simulation results and experiment results shows that the simulating results of shaped steel tube are in good agreement with the on-site data. The model could provide the basis for theoretical research and engineering applications of shaped steel tube rolling process. 相似文献
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摘要:为了解决CPE顶管机组轧制薄壁无缝管实际生产中出现的管壁拉凹问题,基于某钢管公司114mm CPE顶管机组的装备和工艺条件,借助于有限元分析软件Simufact,对42CrMo4钢管典型规格111mm×435mm顶管过程的辊模力、各机架轧件出口壁厚、应力应变及相对滑动速度进行了分析。结果表明,顶管过程中,减壁量较大的机架之间存在张力作用,机架减壁量越大,轧件在辊缝处壁厚减薄量越大;轧件在辊缝处所受到的轴向应力均为拉应力,在靠近轧件头部一段距离内轧件所受到的轴向拉应力较大,发生壁厚拉凹的倾向性增大。机架过大的减壁量和减壁率引起的轧件沿孔型宽度方向的严重不均匀变形、机架间大的张力及芯棒与轧件间过大的速度差引起的芯棒拽入力是顶管过程管壁拉凹缺陷产生的主要原因。 相似文献