Zhu Xinglin, Dong Erting, Qiao Xiaomin, Liu Dong
School of Materials Science and Engineering, Henan Institute of Technology, Xinxiang 453000, China.
Xinxiang Key Laboratory of Materials Processing Technology and Mould, Xinxiang 453000, China.
Materials (Basel). 2024 Sep 15;17(18):4538. doi: 10.3390/ma17184538.
The forming quality of profiled ring rolling not only encompasses macroscopic accuracy but also emphasizes the microstructure. Due to the multiple process parameters and complex metal flow during profiled ring rolling, the various forming defects are difficult to control and difficult to study theoretically. The objective of this study is to establish a comprehensive method for evaluating the forming quality of profiled rings, which considers both the macroscopic forming accuracy and the microstructure. Firstly, the synthetic size factor was defined, and the evolutionary relation between the section forming rate and the diameter growth rate of E-section ring rolling was analyzed in detail. The synthetic size factor can be used to describe the dimensional evolution and evaluate the forming accuracy of the profiled ring rolling process. Taking into full consideration the features of intermittent deformation in local areas, a microstructure evolution model of the Inconel718 alloy during E-section ring rolling, which can accurately predict the recrystallization volume fraction and average grain size of the final ring, was established. Then, combined with finite element simulation, the influence of the rotation speed of the driving roll on the macro-size evolution and microstructure was systematically analyzed. The results indicate that there is often a discrepancy between dimensional accuracy and microstructure uniformity in the optimization trend. For instance, the higher the rotation speed of the driving roll is, the more uniform the microstructure is, but the more difficult it is for the section profile to form. Finally, combined with response surface methodology (RSM), multi-parameter optimization was carried out with section forming accuracy and grain uniformity as the optimization objectives. By using the optimal parameters, an E-section ring with a complete profile and a uniform microstructure was obtained, with a maximum prediction error of the recrystallization volume fraction lower than 5%. The results show that the macroscopic and microscopic quality evaluation methods proposed in this study, as well as the optimization method combining RSM, can be effectively applied to the process optimization of profiled ring rolling.
异形环件轧制的成形质量不仅包括宏观精度，还强调微观组织。由于异形环件轧制过程中工艺参数众多且金属流动复杂，各种成形缺陷难以控制且难以从理论上进行研究。本研究的目的是建立一种综合评估异形环件成形质量的方法，该方法兼顾宏观成形精度和微观组织。首先，定义了综合尺寸因子，并详细分析了E形截面环件轧制中截面成形率与直径增长率之间的演变关系。综合尺寸因子可用于描述尺寸演变并评估异形环件轧制过程的成形精度。充分考虑局部区域间歇变形的特点，建立了Inconel718合金在E形截面环件轧制过程中的微观组织演变模型，该模型能够准确预测最终环件的再结晶体积分数和平均晶粒尺寸。然后，结合有限元模拟，系统分析了主动辊转速对宏观尺寸演变和微观组织的影响。结果表明，在优化趋势方面，尺寸精度和微观组织均匀性之间往往存在差异。例如，主动辊转速越高，微观组织越均匀，但截面轮廓越难成形。最后，结合响应面法（RSM），以截面成形精度和晶粒均匀性为优化目标进行了多参数优化。通过使用最优参数，获得了轮廓完整且微观组织均匀的E形截面环件，再结晶体积分数的最大预测误差低于5%。结果表明，本研究提出的宏观和微观质量评估方法以及结合RSM的优化方法能够有效地应用于异形环件轧制的工艺优化。
