楔横轧轴类件轴向闭开联合轧制近成形与成性理论研究

This proposal employs modern numerical technology and rolling experiment to study the theory of the near net forming shape and characteristics on shaft parts by axial closed-open combined cross wedge rolling:Deduce the coupling curve between the axial rolling bulge and the transverse deformation in the rolling process; determine the stable rolling conditions of axial closed cross wedge rolling and the coupling relation between optimum quality on the workpiece end and the rolling length;Analyze the rule of change of all stages of stress, strain and displacement field in the closed-open combined rolling process, and clarify its forming mechanism; Verify the rule of change of mechanical parameters between forming process parameters and rolling parameters in the closed-open combined rolling process; Analyze the reverse flow rule of workpiece rolled by closed rolling in the open rolling process, find out quantitative relation of workpiece quality between mechanical parameters and rolling parameters, establish the workpiece quality control forming theory of axial closed-open combined rolling; Study the quantitative relation of workpieces' crystalline size and distribution with mechanical parameters, obtain the optimal parameters principle by organization uniformity control of axial closed-open combined rolling, establish rolling property theory of axial closed-open combined rolling. Accomplish these fundamental researches to establish the theory of the near net forming shape and characteristics on shaft parts by axial closed-open combined cross wedge rolling, provide the theoretical basis for developing high-performance precise volume forming technique, so as to help realize near 100% materials utilization of cross wedge rolling and ro improve the quality of rolled parts and also the equipment service life.

用现代数值技术和轧制实验等方法进行楔横轧轴类件轴向闭开联合轧制近成形与成性理论研究：推导闭式轧制过程中轧件轴向凸起与横向变形的耦合曲线、确定轧件端部最优质量与可轧长度理论关系及稳定轧制条件；分析轴向闭开联合轧制各阶段应力场、应变场和位移场的变化规律，阐明其成形机理；探究轧制过程中力能参数随成形工艺参数和轧制参数的变化规律，分析闭式轧制完成部分的轧件在开式轧制中金属反向流动规律，及该部分轧制质量与工艺参数和轧制参数的定量关系，建立轴向闭开联合轧制轧件质量成形理论。研究轧制各阶段的轧件晶粒大小、分布均匀性及与工艺参数的定量关系，给出轴向闭开联合轧制组织均匀性控制的最优参数确定原则，建立轴向闭开联合轧制成性理论。完成上述基础研究，建立楔横轧轴类件轴向闭开联合轧制近成形与成性理论,发展我国零件高性能精确体积成形技术，为实现楔横轧近100%材料利用率，提高零件产品质量和装备服役寿命奠定理论基础。

针针对楔横轧成形存在表层与心部金属不同步流动、轧件金属易横向流动等变形不均匀，导致轧件需预留端部料头和表面椭圆化，材料利用率难以突破85%技术瓶颈难题，项目提出闭开联合轧制新技术，用现代数值模拟和轧制实验等方法，进行楔横轧轴类件轴向闭开联合轧制近成形与成性理论研究：阐明闭式轧制过程中轧件轴向凸起产生机制、确定轧件端部最优质量与可轧长度理论关系及稳定轧制条件；分析轴向闭开联合轧制各阶段应力场、应变场和位移场的变化规律，阐明闭式轧制完成部分的轧件在开式轧制中金属反向流动规律、轧制质量与工艺参数和轧制参数的定量关系；探究轧制过程中力能参数随成形工艺参数和轧制参数的变化规律，建立轴向闭开联合轧制轧件质量成形理论。研究轧制各阶段的轧件晶粒大小、分布均匀性及与工艺参数的定量关系，给出轴向闭开联合轧制组织均匀性控制的最优参数确定原则，建立轴向闭开联合轧制成性理论。在上述研究基础上，给出了控制轧件变形不均匀的措施。理论与实验研究结果表明，闭开联合轧制技术是可行的，宏观上将轧件端部凹心显著降低，有效提高了轧件表面与端部质量，轧件材料利用率提高到95%以上；微观上轧件晶粒得到进一步均匀细化，显著提高了产品性能。项目研究结果为丰富和完善楔横轧成形理论、发展我国零件高性能精确体积成形技术，实现楔横轧近100%材料利用率，提高零件产品质量和服役寿命提供理论基础。