面向极大尺度环件径-轴向稳定轧制的环件匀速长大状态精准闭环控制方法

Towards Extremely Large-scale Radial-axial Ring Rolling for Constant Ring Growth State with Accurate Closed-loop Control Method

环件径-轴向轧制是极大尺度无缝环件整体塑性成形的不可替代技术,主轧阶段环件匀速长大是径-轴向稳定轧制的一种理想状态,如何通过合理的控制策略获得逼近理想设计的环件匀速长大状态,是极大尺度环件径-轴向轧制过程稳定性控制的关键问题。为解决这样的问题,提出一种面向实际轧制过程的设计驱动下环件外径长大速度理论控制方法。首先提出轧制过程中环件实时尺寸的测量方法实现对长大速度的实时监控;其次在ABAQUS平台中通过用户子程序VUAMP进行二次开发建立一种设计驱动下环件长大速度控制方法(理想状态控制方法),此方法需要的参数由等效尺寸模型计算以消除环件几何不规则引起的误差(尺寸修正控制方法),最后通过误差实时反馈调控策略消除动态缺陷引起的小幅误差使得长大速度精确逼近目标值,形成一种过程与设计相结合的主轧阶段外径匀速长大理想状态的精准闭环控制模型(基于尺寸修正的闭环控制方法)。结果表明,稳定的长大速度能够降低主轧阶段环件的偏心程度同时改善最终环件的椭圆度,为实际极大尺度环件轧制过程稳健控制提供了可靠手段。

Radial-axial ring rolling(RARR)is an irreplaceable technology for the overall plastic forming of large-scale seamless rings.The constant growth velocity of the ring during the main rolling stage is an ideal state for radial-axial stable rolling,how to obtain the constant growth state of the ring that is close to the ideal design through a reasonable control strategy is a key issue in the stability control of the large-scale RARR process.In order to solve this problem,a theoretical control method for the growth rate of ring outer diameter under design-driven for the actual rolling process is proposed.Firstly,a method for measuring the real-time size of the ring during the rolling process is proposed to realize real-time monitoring of the ring growth velocity;Secondly,a design-driven ring growth speed control method(Ideal state control method)is establish by secondary development through user subroutine VUAMP in the ABAQUS platform and the parameters required by this method are calculated by the equivalent size model to eliminate the errors caused by geometry irregularities of the ring(Size correction control method).Finally,the small error caused by dynamic defects is eliminated through the real-time error feedback control strategy,so that the growth rate can accurately approach the target value and a precise closed-loop control model of constant growth velocity of outer diameter in main rolling stage that combines the process and design is formed(Closed-loop control method based on size correction).The result shows that the constant growth velocity can reduce the eccentricity of the ring in the main rolling stage and improve the ovality of the final ring,which can provide a reliable method for the robust control of the actual extremely large-scale RARR process.