The control manner during the process to ensure the quality of pipe products mainly relies on the operator’s experience, so it is very necessary to study the setting round process and obtain its spring-back law. The ...The control manner during the process to ensure the quality of pipe products mainly relies on the operator’s experience, so it is very necessary to study the setting round process and obtain its spring-back law. The setting round process is shaping an oval section pipe into circular section, so it is difficult to provide a quantificational analysis for its spring-back process because of the curvature inequality of pipe section neutral layer. However, the spring-back law of the circle-oval process can be easily predicted. The experimental method is firstly used to establish the equivalent effect between the setting round process and the circle-oval process. The setting round process can be converted into the circle-oval process. There are two difficulties in the theoretical analysis for the circle-oval process: elastic-plastic bending problem of curved beam; statically indeterminate problem. A quantitative analytic method for the circle-oval process is presented on the basis of combination of the spring-back law of plane curved beam with the element dividing idea in finite element method. The ovality after unloading versus the relative reduction is plotted with analytical and experimental results respectively, which shows a fair agreement. Finally, the method of quantitative prediction of reduction for large pipe setting round is given based on the equivalent effect and the analytical results. Five pipes, which are needed to be set round, are used to carry out experiment so as to verify this method. The results of verification experiment indicates that, in the experimental range, the residual ovality are all under 0.35% after the once only setting round with the theoretical prediction reductions. It is much less than the 1% requirement of pipe standard. Applying the established theoretical analysis is able to correct the pipe ovality with sufficient accuracy, which provides theoretical direction to plant use.展开更多
The mechanical properties of the steel pipe rolled with continuously casting round billet after determining the chemical composition in steel were studied.The results show that the total reduction ratio should be high...The mechanical properties of the steel pipe rolled with continuously casting round billet after determining the chemical composition in steel were studied.The results show that the total reduction ratio should be higher than 5.2 when the line pipes of grade B,grade 20 and other general seamless pipe were rolled with continuously casting round billet.And the total reduction ratio should be higher than 10.2 and the grain size should be controlled more than grade 7 for casing of oil countryside tubular goods(OCTG).展开更多
【目的】托辊作为圆管带式输送机的关键部件,其接触力大小直接决定托辊的使用寿命;而托辊间距的布置方式对输送机的稳定运行及传输效率同样至关重要。【方法】采用Abaqus软件对圆管带式输送机直线段与凸凹弧段进行离散单元法-有限单元法...【目的】托辊作为圆管带式输送机的关键部件,其接触力大小直接决定托辊的使用寿命;而托辊间距的布置方式对输送机的稳定运行及传输效率同样至关重要。【方法】采用Abaqus软件对圆管带式输送机直线段与凸凹弧段进行离散单元法-有限单元法(Discrete Element Method-Finite Element Method,DEM-FEM)耦合仿真分析,得出不同线路上托辊接触力的分布情况,同时结合理论分析验证了模型的可行性;改变托辊间距,研究这一因素对曲线段上同一托辊组中各托辊接触力分布的影响规律,并与直线段进行对比,得出不同输送线路上托辊间距与直线段的布置差异。【结果】研究为实际工程中托辊选型及间距的调整和优化提供了有价值的参考和指导。展开更多
基金supported by National Natural Science Foundation of China (Grant No. 51175452)Hebei Provincial Natural Science Foundation of China (Grant No. E2012203061)
文摘The control manner during the process to ensure the quality of pipe products mainly relies on the operator’s experience, so it is very necessary to study the setting round process and obtain its spring-back law. The setting round process is shaping an oval section pipe into circular section, so it is difficult to provide a quantificational analysis for its spring-back process because of the curvature inequality of pipe section neutral layer. However, the spring-back law of the circle-oval process can be easily predicted. The experimental method is firstly used to establish the equivalent effect between the setting round process and the circle-oval process. The setting round process can be converted into the circle-oval process. There are two difficulties in the theoretical analysis for the circle-oval process: elastic-plastic bending problem of curved beam; statically indeterminate problem. A quantitative analytic method for the circle-oval process is presented on the basis of combination of the spring-back law of plane curved beam with the element dividing idea in finite element method. The ovality after unloading versus the relative reduction is plotted with analytical and experimental results respectively, which shows a fair agreement. Finally, the method of quantitative prediction of reduction for large pipe setting round is given based on the equivalent effect and the analytical results. Five pipes, which are needed to be set round, are used to carry out experiment so as to verify this method. The results of verification experiment indicates that, in the experimental range, the residual ovality are all under 0.35% after the once only setting round with the theoretical prediction reductions. It is much less than the 1% requirement of pipe standard. Applying the established theoretical analysis is able to correct the pipe ovality with sufficient accuracy, which provides theoretical direction to plant use.
文摘The mechanical properties of the steel pipe rolled with continuously casting round billet after determining the chemical composition in steel were studied.The results show that the total reduction ratio should be higher than 5.2 when the line pipes of grade B,grade 20 and other general seamless pipe were rolled with continuously casting round billet.And the total reduction ratio should be higher than 10.2 and the grain size should be controlled more than grade 7 for casing of oil countryside tubular goods(OCTG).
文摘【目的】托辊作为圆管带式输送机的关键部件,其接触力大小直接决定托辊的使用寿命;而托辊间距的布置方式对输送机的稳定运行及传输效率同样至关重要。【方法】采用Abaqus软件对圆管带式输送机直线段与凸凹弧段进行离散单元法-有限单元法(Discrete Element Method-Finite Element Method,DEM-FEM)耦合仿真分析,得出不同线路上托辊接触力的分布情况,同时结合理论分析验证了模型的可行性;改变托辊间距,研究这一因素对曲线段上同一托辊组中各托辊接触力分布的影响规律,并与直线段进行对比,得出不同输送线路上托辊间距与直线段的布置差异。【结果】研究为实际工程中托辊选型及间距的调整和优化提供了有价值的参考和指导。
