共查询到19条相似文献,搜索用时 171 毫秒
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在空心轴楔横轧多楔轧制中,控制壁厚均匀性是衡量车轴成形质量的重要标准.本文先分析空心轴楔横轧多楔轧制的稳定轧制条件,得到了确定空心车轴楔横轧压扁失稳的准则.在此基础上,基于DEFORM-3D软件,建立楔横轧多楔同步轧制高铁空心车轴的三维刚塑性有限元模型,分析展宽角、成形角等工艺参数对壁厚均匀性的影响,获得了工艺参数影响轧制空心车轴壁厚变化的规律.结果表明:成形角越大,壁厚均匀性越好;展宽角越大,壁厚均匀性越好,但在展宽角大于10°时,壁厚均匀性反而下降.基于多楔轧制实验,轧制1∶5缩比的空心车轴,测量了轧制力矩和轧制空心轴的壁厚,与仿真结果作比较,相对误差均在10%以内,验证了所建有限元模型的正确性. 相似文献
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机械结构轻量化的主要途径是在结构上采用空心轴.近年来, 采用楔横轧带芯棒轧制空心轴类件的工艺得到了较广泛的关注.厚壁空心轴类件在楔横轧轧制过程中易发生“失圆”现象.本文通过热压缩实验研究了25CrMo4合金钢在楔横轧变形条件下热变形行为, 获得其真应力-应变曲线.在此基础上, 基于Deform-3D有限元软件, 建立25CrMo4厚壁空心轴楔横轧有限元仿真模型, 分析厚壁空心轴楔横轧成形机理, 研究得出断面收缩率、成形角、展宽角对轧件不圆度的影响规律: 断面收缩率增大, 不圆度减小; 成形角增大不圆度减小, 轧制温度越高减小趋势越明显; 展宽角增大不圆度增大, 提高轧制温度抑制增大趋势.选取部分工艺参数进行楔横轧验证实验, 对比了有限元仿真结果和实验结果, 表明有限元仿真模型预测精度较高. 相似文献
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工艺参数对楔横轧特大型轧件内部应力影响分析 总被引:4,自引:0,他引:4
楔横轧成形特大型轧件为复杂的三维变形,其内部应力变化规律复杂,至今缺乏深入研究与本质理解,严重影响楔横轧的应用与发展。采用有限元先进数值方法模拟楔横轧特大型轧件成形过程,详细分析成形过程中轧件内部中心点的应力变化规律,阐明成形角、展宽角和断面收缩率三个主要工艺参数对特大型轧件内部应力的影响关系,为合理选取楔横轧特大型轧件模具工艺参数、开发设计特大型楔横轧机提供重要的理论依据。 相似文献
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Yan-zhao LUO Jiong-ming ZHANG Qiang LIU Mao-kang LI Yi-tong HAN Yi-fei CAO 《钢铁研究学报(英文版)》2014,21(4):476-481
In the continuous casting of steels,surface transversal cracks are often found.These defects may severely influence the final quality of the products.The evolution of transversal V-shaped cracks with different depth on the surface of a continuously cast steel slab during hot rolling was studied.The artificial V-shaped cracks were made on the surface.The rolling process parameters from an industrial rolling mill have been used as a reference.The specimens of rolled workpiece in intermediate slabs were obtained after different rolling passes.The morphology of surface crack and microstructure evolution in the rolling process were investigated by optical microscopy.The results show that the depth of surface transversal crack gradually decreased with the increase of rolling passes.The grain size of ferrite and pearlite on the sample surface also gradually reduced.The microstructures around cracks with the different depth are almost identical,without direct correlation with the initial crack depth. 相似文献
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M. V. Filippova M. V. Temlyantsev V. N. Peretyat’ko E. E. Prudkii 《Steel in Translation》2017,47(7):435-439
The rolling of balls (diameter 93 and 125 mm) of precise mass in helical grooves is simulated by means of QForm-3D and DEFORM-3D software. A model of a virtual rolling mill is created. Analysis of the stress state at characteristic points along the rolling axis focuses on the effective stress, the components of the stress tensor, and the mean normal stress. The mass of balls rolled on new and worn rollers is measured. The quality of internal metal layers is verified, and the hardness of rolled balls over the vertical and horizontal symmetry axes is measured. Modeling of ball rolling shows that the hot blank (a rod of hot-rolled steel) is satisfactorily captured by the rollers. Rolling is stable, without slipping. The blank completely fills the grooves; no gaps are observed between the metal and the walls. The crosslinks between the balls are completely eliminated within the rollers. The crosslinks are cut by the rim of the rollers and pressed into the body of the ball. The individual balls continue to roll along the finishing section of the groove; the stubs of the crosslinks are smoothed; and a completely shaped ball with a smooth surface emerges from the rollers. In modeling the stress–strain state, all the components of the stress tensor are negative. In other words, all the components of the stress tensor are compressive in rolling of the balls. Statistical analysis of the data from weighing of the rolled balls (diameter 93 and 125 mm) shows that the mass deviates from the required value by no more than 1%. Measurement of the hardness over the diametric cross section of the balls shows that there is no decline in hardness in the internal layers. That indicates high quality of the ball core. 相似文献
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Cross-Wedge Rolling of Shafts With an Eccentric Step 总被引:1,自引:0,他引:1
Zbigniew Pater 《钢铁研究学报(英文版)》2011,18(6):26-30
A new concept for forming eccentric shafts on the basis of the cross wedge rolling (CWR) process was presented. This concept was based on the application of special guides, which, by acting on a billet, lead to its controlled movement in the vertical direction. This movement made possible eccentric cutting of tools into the billet. FEM calculations and experimental rolling tests clearly confirmed the effectiveness of the proposed forming method. 相似文献
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通过对U3-500H型轧钢机轧制过程进行分析,根据H型钢生产工艺参数,采用西姆斯公式和多元回归的方法,建立了其H型钢轧钢机轧制力数学模型,并编写matlab程序计算数学模型的回归系数,通过求解实例分别计算了3种规格的H型钢立辊和水平辊回归模型的系数。针对水平辊轧制力模型在实际应用中的局限性,采用ADAMS对水平辊轧制力进行虚拟仿真计算分析。结果表明:H型轧钢机不仅在竖直方向受到巨大的峰值载荷作用,同时在水平方向也受到极大的载荷作用,在重载条件下轧辊微小的裂纹极易迅速扩展,这点应特别注意;虚拟仿真的轧制力与实测值误差为3%~6%。 相似文献