X70管线钢液相扩散焊数值模拟

发布时间：2018-06-11 17:07

本文选题：TLP + 数值模拟　；参考：《北京石油化工学院》2017年硕士论文

【摘要】：瞬时液相扩散焊(TLP)是一种特殊的材料连接方法,具有焊接温度低、残余应力小、余高小等优点。利用有限元分析方法对TLP进行数值模拟,能够分析和预测焊缝接头的性能,具有节省材料、人力,提高效率的优点。本文以X70管线钢为母材,进行TLP数值模拟分析。首先分析了电磁感应加热理论,对电磁场和电磁感应加热数学模型进行了分析,进而,对电磁感应加热磁热耦合热源模型进行了说明,并结合本实验的实际情况,分析了磁热耦合模型在本实验中的适用性,得出结论认为无法利用磁热耦合热源进行模拟计算。之后通过对实验实际条件的分析,将感应加热过程进行简化,建立了替代热源模型,并利用替代模型进行模拟,与实际实验的温度场结果进行比较,吻合较好。建立了TLP焊接几何模型,与热源模型一起构成了完整的数值分析模型。考虑了中间层的热效应以及连接面的点接触,在模型的建立过程中提出了一系列假设,在保证计算结果精度的前提下尽可能的简化计算过程,增加计算效率。利用模型对TLP焊接的温度场和残余应力场进行了分析,分别以保温温度、保温时间为变量计算温度场和残余应力场的结果,分析了在各参数影响下温度场和残余应力场的变化规律。结果表明,保温温度增加,残余应力增加;保温时间增加,残余应力减小。分析了焊后焊缝的金相组织,以保温温度、保温时间和焊接压力为参数,分析了各参数对焊缝组织的影响效果,得出了各影响因素的影响规律。结果表明,保温温度越高,保温时间越长,越有利于形成稳定的焊缝组织。
[Abstract]:Transient liquid phase diffusion welding (TLP) is a special material bonding method, which has the advantages of low welding temperature, low residual stress and low residual height. The numerical simulation of TLP using finite element analysis method can analyze and predict the performance of weld joint, which has the advantages of saving material, manpower and improving efficiency. Taking X 70 pipeline steel as base material, TLP numerical simulation analysis is carried out in this paper. Firstly, the theory of electromagnetic induction heating is analyzed, and the mathematical models of electromagnetic field and electromagnetic induction heating are analyzed. Then, the magneto-heat coupling heat source model of electromagnetic induction heating is explained, and the actual situation of this experiment is combined. The applicability of the magnetocaloric coupling model in this experiment is analyzed, and it is concluded that the magnetothermal coupling heat source can not be used for simulation calculation. After analyzing the actual conditions of the experiment, the induction heating process is simplified, and the model of alternative heat source is established. The model is simulated by using the substitute model, and the results are in good agreement with the results of the actual experimental temperature field. The geometry model of TLP welding is established and a complete numerical analysis model is constructed together with the heat source model. Taking into account the thermal effect of the intermediate layer and the point contact of the connection surface, a series of assumptions are put forward in the process of establishing the model, which can simplify the calculation process as much as possible and increase the calculation efficiency under the premise of ensuring the accuracy of the calculation results. The temperature field and residual stress field of TLP welding were analyzed by using the model. The results of temperature field and residual stress field were calculated by using heat preservation temperature and holding time as variables, respectively. The variation of temperature field and residual stress field under the influence of various parameters are analyzed. The results show that the residual stress increases with the increase of the holding temperature, and the residual stress decreases with the increase of the holding time. The metallographic structure of welding seam after welding is analyzed. With the parameters of holding temperature, holding time and welding pressure as parameters, the effect of each parameter on weld microstructure is analyzed, and the influence law of each influencing factor is obtained. The results show that the higher the holding temperature, the longer the holding time, the more favorable to the formation of stable weld microstructure.
【学位授予单位】：北京石油化工学院
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG457.11

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