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Peng Y.,Wuhan University of Technology | Song Y.,Zhangjiagang Hailu Annular Forgings Co. | Zeng X.,Wuhan University of Technology | Qian D.,Wuhan University of Technology
Zhongguo Jixie Gongcheng/China Mechanical Engineering

Radial-axial ring rolling process is complex dynamic deformation process with multi-movement coupled effects, which easily causes variable instability phenomenon, one of that is the ring climb along the axial direction in radial-pass. Firstly, the mechanics theory was used to analyze the stress state of the ring in rolling process, so as to reveal the mechanical mechanism of climbing; then, a suppressive method was proposed based on optimizing the guide rollers' shape and distribution; lastly, the method was verified by FE simulation and experiment. The results provide scientific guidance for resolving the axial climbing in practical manufacture. Source

Dai Y.,Zhangjiagang Hailu Annular Forgings Co. | Chen H.,Jiangsu University | Qian X.,Jiangsu University
Jinshu Rechuli/Heat Treatment of Metals

Crack and coarse grain problems appeared in 42CrMo steel large ring forging after heat treatment were analyzed theoretically, optimal heat treatment process was proposed. The microstructure and mechanical properties of ring forging treated by improved processes were analyzed. The results show that, by normalizing at 860°C after forging then quenching in water from 840°C, and tempering at 610°C, microstructure of the ring forging can be fined to a certain degree, and good mechanical properties can also be obtained, and the heat treatment quality is stable, which meets the technical requirements of the ring forgings very well. Source

Lv Z.-H.,Hubei University of Automotive Technology | Wang X.-K.,Hubei University of Automotive Technology | Wang X.-K.,Xian Jiaotong University | Hua L.,Hubei University of Automotive Technology | And 4 more authors.
Suxing Gongcheng Xuebao/Journal of Plasticity Engineering

With the accelerated development of China's energy equipment project, there is a large demand for oil and gas pipeline joints, double-side flange and high pressure valve body. Combined ring rolling is a new technology to form this kind of rings. Aiming at the problem of the combined ring rolling process with low accuracy and large dimension tolerance, a combined ring rolling control method for flange rings of oil and gas transmission pipeline is proposed; then the interrelationships and influence rules between ring product's geometrical dimensions and ring blank's weight error during the combined ring rolling are analyzed, and the corresponding correction mathematical model of the rolls' position is established. Finally, the combined ring rolling experiments were conducted to validate the geometric dimension control method. Two ring blanks with different weights were chosen during the experiments. The results show that the formed rings' geometrical dimensions of the experiments are in good agreement with the calculated values of the mathematical model. The conclusions have practical guiding significance for precisely forming the flange rings of oil and gas transmission pipeline. © 2016, Editorial Board of Journal of Plasticity Engineering. All right reserved. Source

Xiaokai W.,Hubei University of Automotive Technology | Xiaokai W.,Xian Jiaotong University | Dehui W.,Hubei University of Automotive Technology | Dehui W.,Hubei Collaborative Innovation Center for Automotive Components Technology | And 5 more authors.
MATEC Web of Conferences

The automatic loading and unloading technology is the key to the automatic ring production line. In this paper, the automatic vertical hot ring rolling (VHRR) process is taken as the target, the method of the loading and unloading for VHRR is proposed, and the mechanical structure of loading and unloading system is designed, The virtual prototype model of VHRR mill and loading and unloading mechanism is established, and the coordinated control method of VHRR mill and loading and unloading auxiliaries is studied, the movement trace and dynamic characteristic of the critical components are obtained. Finally, a series of hot ring rolling tests are conducted on the VHRR mill, and the production rhythm and the formed rings' geometric precision are analysed. The tests results show that the loading and unloading technology can meet the high quality and high efficiency ring production requirement. The research conclusions have practical significance for the large-scale automatic ring production. © 2015 Owned by the authors, published by EDP Sciences. Source

Pan Y.,Wuhan University of Technology | Qian D.-S.,Wuhan University of Technology | Hua L.,Wuhan University of Technology | Wu J.-S.,Zhangjiagang Hailu Annular Forgings Co. | And 2 more authors.
Suxing Gongcheng Xuebao/Journal of Plasticity Engineering

As there are few research on the rolling technology and equipments for the rings over 5 m diameter at home now, the simulation and experimental research on the rolling technique of Φ 9 m wind-tower flange rings used in large wind power equipments were carried out on the self-developed RAM9000 large NC radial-axial rolling mill which is capable of rolling rings with maximum diameter 9 m. Based on the combination of design theories of ring rolling process and practical experience, process parameters of Φ9 m super large ring rolling were given. Focus on the forming characteristics of super large rings, a new feed specification was proposed. Using finite element simulation software ABAQUS, simulation analysis of rolling was taken. Taking the simulation results as guidance, a Φ 9 m wind tower flange ring was successfully formed on the RAM9000 NC radial-axial rolling mill. Research result lays an important foundation for promoting the development and application of domestic rolling technology of super large rings. Source

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