小直径无缝钢管短流程连轧特征与关键技术研究

发布时间：2018-02-28 06:24

本文关键词： 无缝钢管小直径三辊连轧芯棒无网格法数值仿真　出处：《太原科技大学》2016年博士论文　论文类型：学位论文

【摘要】：无缝钢管在国民经济建设中应用广泛,是一种不可缺少的经济断面钢材。小直径钢管国内外需求逐年增大,该类产品的生产设备数量巨大。而我国国内生产工艺以冷拔、冷拉、挤压为主,这些生产工艺落后,环境污染严重,能耗惊人。随着人们对环境保护,节能降耗等方面越来越高的要求,这些设备及工艺已被列为淘汰之列。三辊连轧机组具有生产工艺先进、生产节奏快、污染排放低等优点,使其成为小直径钢管生产的推荐机型。然而,现存的三辊连轧机组均针对大直径荒管生产设计,小直径钢管连轧工艺及设备还处于探索研究阶段,小直径钢管连轧工艺研究势在必行。因此,开展小直径无缝钢管短流程连轧工艺过程的基本理论及仿真技术研究,掌握小直径钢管连轧变形机理、成形规律,对进一步简化设备、工艺设计过程,节能减排,缩短产品生产工序,降低企业设备、人力投入,提升企业竞争力具有重要的意义和是实用价值。已有的三辊连轧孔型设计理论难以解决钢管小直径条件下的连轧工艺设计问题,加之短流程工艺,机架数目减少,更增大了孔型设计的难度。为了解决以上问题,本文首先结合理论、实际生产经验,对小直径钢管连轧变形过程进行理论分析,揭示小直径钢管连轧变形特征,推导了小直径钢管连轧工艺孔型设计方法。为了深入研究小直径钢管连轧变形特征,建立了钢管连轧变形过程三维无网格法数值仿真模型。该模型使用移动最小二乘法构建未知场近似函数,结合双重点法简化近似函数的构建及求导过程;使用局部修正法对近似函数进行修正,以便精确、快速施加边界条件;使用加权最小二乘法构建速度场刚度矩阵,使用配点法直接构建温度场刚度矩阵;采用间接耦合法将速度场与温度场耦合求解。通过仿真研究了连轧过程几何形状变化、温度场分布、应力应变场分布,且该模型通过了实验验证,验证了其有效性。通过对不同孔型、不同规格产品的系列仿真与实验,研究了小直径钢管金属变形特征、孔型与轧辊转速对轧制力能参数的影响、宽展变形规律、金属流动规律;开发了小直径钢管连轧工艺技术,经实验证明其理论是可靠的,工艺技术是可行的。
[Abstract]:Seamless steel pipe is widely used in national economic construction and is an indispensable economic section steel. The domestic and foreign demand for small diameter steel pipe is increasing year by year, and the production equipment of this kind of products is huge. Extrusion is the main factor. These production processes are backward, environmental pollution is serious, and energy consumption is staggering. With the increasing demand for environmental protection, energy saving and consumption reduction, These equipments and processes have been listed in the list of elimination. The three-high continuous rolling mill has the advantages of advanced production technology, fast production rhythm and low pollution emission, which makes it a recommended model for the production of small diameter steel tubes. The existing three-high continuous rolling mill is designed for the production of large diameter steel tube, and the continuous rolling process and equipment of small diameter steel pipe are still in the stage of exploration and research, so it is imperative to study the continuous rolling process of small diameter steel pipe. The basic theory and simulation technology of short process continuous rolling process of small diameter seamless steel tube are studied, and the deformation mechanism and forming law of small diameter seamless steel pipe are grasped, which can further simplify the equipment, process design process, save energy and reduce emissions. It is of great significance and practical value to shorten the production process of products, reduce the input of equipment and manpower, and promote the competitiveness of enterprises. The existing theory of pass design for three-roll continuous rolling is difficult to solve the problem of continuous rolling process design under the condition of small diameter of steel pipe. In addition, because of the short process process, the number of stand is reduced, and the difficulty of pass design is increased. In order to solve the above problems, this paper firstly analyzes the deformation process of small diameter steel tube by combining the theory and practical production experience. The characteristics of continuous rolling deformation of small diameter steel tube are revealed, and the pass design method of continuous rolling process of small diameter steel pipe is deduced, in order to study the deformation characteristics of continuous rolling of small diameter steel tube in depth, A three-dimensional meshless numerical simulation model for continuous steel tube rolling process is established, in which the unknown field approximation function is constructed by moving least square method, and the construction and derivation process of the approximate function is simplified with the dual point method. The local correction method is used to modify the approximate function so that the boundary conditions can be applied accurately and quickly, the velocity field stiffness matrix is constructed by weighted least square method, and the temperature field stiffness matrix is constructed directly by collocation method. The coupling of velocity field and temperature field is solved by indirect coupling method. The geometric shape change, temperature field distribution, stress and strain field distribution in continuous rolling process are studied by simulation, and the model is verified by experiments. Through the series simulation and experiment of different pass and different specification products, the metal deformation characteristics of small diameter steel tube, the influence of pass and roll speed on rolling force and energy parameters, and the law of wide deformation are studied. The technology of continuous rolling of small diameter steel pipe has been developed. The theory is proved to be reliable and the technology is feasible.
【学位授予单位】：太原科技大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：TG335.71

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