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采用有限元软件DEFORM-3D对楔横轧厚壁空心轴进行热力耦合数值模拟,得到了工艺参数对楔横轧厚壁空心轴不圆度的影响规律。结果表明,在成形角35°~45°、展宽角4°~7°、断面收缩率35%~65%、轧制温度900℃~1100℃时,轧件不圆度与成形角及断面收缩率的变化成反比,与展宽角及轧制温度变化成正比。采用H630楔横轧机进行轧制实验验证了有限元模型的正确性。模拟与实验结果证明,轧件横截面失圆是楔横轧成形厚壁空心轴类件常见的质量问题;变形区金属沿轴向的流动受到未变形金属的阻碍,是造成不圆度在轧件的对称面上最大并沿轴向逐渐减小的原因。研究结果为确定楔横轧厚壁空心轴的工艺参数提供了理论依据。 相似文献
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利用Gleeble-2000D热模拟机、550 mm轧机、扫描电镜等研究了终轧温度和冷却工艺对铁素体贝氏体双相钢组织和性能的影响。首先,在水冷-空冷-水冷模式下研究终轧温度对显微组织和力学性能影响,结果表明:随终轧温度降低,基体组织带状加剧,且铁素体形态由多边形转变为沿轧制方向变形的椭圆形;当终轧温度低于800℃时,铁素体比例明显增加,贝氏体比例下降,抗拉强度下降。其次,在850℃的终轧温度下研究了冷却工艺对显微组织和力学性能的影响,结果表明:当终轧后冷却方式为水冷时,基体组织以准多边形铁素体和针状铁素体为主,伸长率较低;终轧后采用水冷-空冷-水冷方式冷却时,基体组织以块状铁素体和贝氏体为主,伸长率较高。 相似文献
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由于楔横轧的零件力学性能优良,广泛用于轧制普通轴.但是轧制齿轮轴的研究几乎空白.提出了齿轮范成法加工原理应用于楔横轧技术中而成形齿轮轴的工艺理论.使用DEFORM-3D有限元软件模拟了楔横轧轧制渐开线直齿齿轮轴成形过程,获得了轧件的塑性等效应变、轧制力能、轮齿成形效果,分析了数值模拟结果. 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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研究了不同的控轧工艺参数对非调质钢组织结构的影响规律,并在非调质钢零件不同部位采用强化控冷技术进行锻后冷却,得到了优化的非调质钢控轧控冷技术。结果表明:非调质钢转向节零件局部强化控冷技术能显著提高零件局部的综合力学性能;在1273~1373 K下,随着应变量ε在0.22~1.61内增加,实验钢原奥氏体晶粒从26~12μm逐渐细化,在该条件下峰值应变约为0.3;在1173~1473 K范围内随着变形温度的降低,变形抗力增大,峰值应变也随之增大,材料原奥氏体晶粒尺寸在20~11μm内逐渐减小;在增大锻压比和局部风冷两种工艺配合下,F40MnV钢可获得较好的综合力学性能。 相似文献
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在不同的轧制温度下,对AZ31镁合金板进行轧制,然后取出轧板立即进行水冷、空冷和退火3种不同的后处理。探究轧制温度和后处理对镁合金显微组织和力学性能的影响。结果表明,轧制温度为250、300℃时,水冷和空冷处理后板材存在着大量的孪晶,350℃时由于轧制温度较高,孪晶的数量很少;水冷处理后的平均晶粒尺寸要小于空冷,空冷处理之后的孪晶数量略少于水冷,当轧制温度为350℃时,退火处理后,晶粒尺寸减小,晶粒趋于等轴状,晶格畸变程度低。在相同的轧制温度下,水冷处理的镁合金板材的屈服强度、抗拉强度和硬度较高;退火处理后可以显著提高板材的伸长率,但屈服强度、抗拉强度略有下降。轧制温度升高时,3种后处理方式之间屈服强度和抗拉强度的最大差值会减小。 相似文献
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M. Yu. Matrosov L. I. Éfron A. A. Kichkina I. V. Lyasotskii 《Metal Science and Heat Treatment》2008,50(3-4):136-141
The phase composition and mechanical properties of rolled thick sheets from pipe steel 05G1MB produced by different modes of controlled rolling with accelerated cooling are studied. The effects of the temperature and deformation regime, of the final rolling temperature, and of the temperature of the start of accelerated cooling on the phase composition of the rolled sheets are considered. The temperature range in which intense reduction during rolling should be avoided in order to keep niobium in the solid solution of the γ-phase and to ensure subsequent segregation of fine niobium carbides in ferrite is determined. 相似文献
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为改进贝氏体钢的生产工艺,对贝氏体超高强钢进行了控轧+空冷(1#钢)、控轧+快冷(2#钢)试验,对轧后钢板组织性能进行了检测分析。结果表明,1#钢(空冷)的显微组织主要为板条贝氏体和铁素体;2#钢(快冷)的显微组织主要为板条马氏体;1#钢和2#钢的抗拉强度都在1 500 MPa以上,并具有良好的塑性、韧性,但1#钢的综合性能优于2#钢。 相似文献
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The present article is dealing with 0.2% C, 0.1% V and 0.02% Nb steel. Billets with 130 mm × 130 mm cross-section were austenitized and hold at 1080 °C. The billets were hot rolled to 22 mm bar diameter. Hot rolling was finished at 980–1000 °C. The final bars were air-cooled. On a parallel way, an experimental hot deformation investigation, on the same steel, was carried out at deformation temperature range 1200–800 °C with the same amount of deformation (97% reduction in area). However, cooling regimes after deformation were air cooling, water quenching to 600 °C followed by air cooling, and water quenching to room temperature. Microstructure investigation was done using both optical and scanning electron microscopes. Further evaluation was done using mechanical testing. The industrial trial has unsatisfied results with poorer yield strength with higher ultimate strength. Bainitic aggregates are detected in the hard phases islands. Air cooling after pilot hot deformation creates banded ferrite–pearlite microstructure with 9.11 μm ferrite grains. However, quick water quenching to 600 °C followed by air cooling develops tempered and softened coarse bainite phase. On the other hand, water quenching to room temperature develops fine bainite texture. Water quenching to 600 °C followed by air cooling is the best regime creating accepted mechanical properties. 相似文献