共查询到19条相似文献,搜索用时 140 毫秒
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运用三维刚塑性有限元DEFORM-3D软件对GH4169合金零件的楔横轧成形进行变形、传热、微观组织演变的耦合数值模拟,揭示轧件在楔横轧成形过程中各个变形阶段(楔入段、展宽段和精整段)微观组织的演变规律,分析轧件平均晶粒尺寸在不同变形阶段变化的具体原因。结果表明,楔横轧成形GH4169合金轧件时,虽然温度低、应变率高,但楔横轧特有的大变形仍能使动态再结晶发生并完成,从而得到细小均匀的晶粒组织;轧件晶粒的细化程度随断面收缩率的增大而增大;轧件在高温下主要发生晶粒长大,因此减小精整段的长度以及缩短进入下道工序的时间,可以避免粗晶的产生,提高成形件的综合力学性能。 相似文献
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非调质钢40MnV楔横轧热变形组织演变模型及数值模拟 总被引:2,自引:0,他引:2
针对非调质钢轴类件楔横轧工艺,以40 MnV钢为研究对象,进行非调质钢高温热变形组织演变规律实验研究.利用Gleeble 3500热模拟实验机,在900 ~1100℃、0.1~ 10 s-1变形条件下进行恒应变速率压缩实验,研究了40 MnV热变形中的力学行为及动态组织变化,并得出了相应奥氏体热变形组织演变晶粒尺寸、再结晶体积分数及晶粒长大数学模型.基于组织演变模型,采用有限元法对空心轴三辊楔横轧热力组织耦合过程进行的数值模拟.通过对比楔横轧成形实验数据结果与模拟计算值,二者吻合良好,验证了该模型可用于楔横轧实际生产过程的组织预报. 相似文献
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Z. Pater 《International Journal of Machine Tools and Manufacture》2000,40(1):49-63
A summary of the cross wedge rolling process (CWR) modelling method being developed by the author is presented in the present study. The forming zone has been divided into several layers to calculate their contact pressure as in the case of the rotational compression process. To verify the accuracy of the proposed calculation method, a WPK-1 experimental rolling stand has been designed and equipped with seven sets of tooling segments having various parameters. Satisfactory consistency has been demonstrated by comparison of predicted theoretical values and results obtained from experiments. 相似文献
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通过分析楔横轧内部空洞(疏松)缺陷的物理性质和形成特征,将内部空洞视为多孔材料,利用多孔材料的刚塑性有限元方法,建立7075铝合金坯料内部空洞缺陷的数值模型。采用相对密度研究成形角、展宽角、断面收缩率对内部空洞缺陷的影响规律。结果显示:内部空洞的扩展主要发生在展宽段,楔入段对它的影响很小。展宽角是影响内部空洞产生的主要因素,而断面收缩率的影响较小。成形角、展宽角、断面收缩率越大,越不易发生内部空洞缺陷。在模具设计时,为了防止铝合金坯料轧制后产生内部空洞缺陷,断面收缩率应选择在55%~65%之间,展宽角在8°~10°之间,成形角在29°~32°之间。 相似文献
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针对汽车变速器中间轴楔横轧传统加工工艺成本高、耗材多、成品率低等问题,提出了采用楔横轧成形方法加工汽车变速器中间轴的工艺方法。针对中间轴变形大、形状复杂、对称性差的问题,提出了双轴对称加工工艺方法。以1701212-Q7中间轴为例设计了对称轧制楔横轧制模具,实践证明了该工艺方法和所设计模具的可靠性。 相似文献
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The internal void of cross wedge rolling (CWR) part can be treated as porous material due to their similar physical property and deformation characteristics. Aiming at the CWR process of aluminum alloy 7075 workpiece, the numerical simulation model for internal void was established by means of the rigid-plastic FEM method for the porous material. The relative density was used to research the influence of three primary parameters on the internal void in CWR process, including the forming angle α1, the stretching angle β and the area reduction ΔA. The experimental results show that the expansion of internal void occurs in the stretching zone, and the knifing zone just has a little influence on it. The stretching angle has a great influence on the internal void, while the area reduction has a small influence on it. The size of internal voids decreases with the increase of area reduction, stretching angle and forming angle. When designing the CWR tool geometry and operating conditions, to prevent the internal void, the area reduction is suggested to be 55%–65%, the stretching angle to be 8°–10°, and the forming angle to be 29°–32°. 相似文献
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楔横轧工艺成形阶梯轴类件时轧件表面缺陷形成条件分析 总被引:3,自引:1,他引:3
依据文献 [4]的模拟实验结果 ,拟定了楔横轧工艺成形阶梯轴类件时轧件表面出现表面缺陷 (蛇皮状或鱼鳞状缺陷 )时的金属流动速度场。以此为基础 ,并借助于上限原理和最小能量原理 ,获得了楔横轧成形阶梯轴时轧件表面缺陷形成的必要条件。同时 ,研究了表面缺陷产生与变形程度、摩擦因数及模具整形段相对长度的关系。从而为估测楔横轧成形阶梯轴类件时轧件表面是否会产生缺陷提供理论指导。 相似文献