30CrMnSiNi2A螺纹件局部感应回火工艺模拟研究
发布时间：2018-07-18 10:15
【摘要】：30CrMnSiNi2A超高强度钢螺纹件在加工和热处理过程中,易在螺纹部位形成应力集中,需要对螺栓类制件的螺纹和退刀槽等部位进行局部回火处理。工件局部回火处理中使用高频感应加热取代落后的铅浴回火工艺已经成为发展趋势。通过数值模拟和实验相结合的方法确定30CrMnSiNi2A螺纹件感应局部回火工艺参数,对于使用绿色环保、高效率的感应加热系统替代落后的传统铅浴回火工艺以及获得高综合使用性能的30CrMnSiNi2A螺纹件具有十分重要的意义。本文从30CrMnSi Ni2A螺纹件感应加热过程电磁-温度场数值模拟研究入手,建立了适合30CrMnSiNi2A螺纹件感应加热局部回火过程的数值计算模型,研究了各工艺参数对30CrMnSiNi2A钢制件感应加热影响规律,并且进行了30CrMnSiNi2A钢小型螺纹类工件局部回火感应线圈的优化设计,并结合感应加热工艺参数和30CrMnSiNi2A钢材料组织性能之间的关系,最终确定了30CrMnSiNi2A钢螺纹类工件感应局部回火的工艺参数。根据实验分析,得出以下结论:(1)30CrMnSiNi2A钢工件感应加热建模分析,包括实体模型的建立,30CrMnSiNi2A材料的热物性参数模型,实体模型的网格划分,边界载荷条件的设置以及加载求解。数值模拟结果和实际测量结果比较发现,数值模拟结果和实验结果相近,对实际操作具有一定的指导意义。(2)感应加热过程中,工件表面温度迅速达到相变温度,在相变点维持一段稳定后工件的温度曲线呈现不同的趋势;电流密度值正相关于感应磁场强度值大小,从而直接影响最终加热温度;电流频率会影响材料的透入深度,进而影响轴件感应加热后的心表温差。高频率能在极短时间内迅速提高材料表面温度,同时提高热效率,但高频阶段频率的增大产生影响越来越不明显,故而频率选择需要综合考虑;线圈厚度对感应温度的影响同电流密度相同,线圈壁厚的设计主要从感应器的功率损耗和经济方面考虑。(3)进行30CrMnSiNi2A螺纹件局部回火感应线圈进行了优化设计,得到的优化线圈为:感应线圈截面为矩形,矩形截面尺寸12×6 mm,线圈壁厚为1 mm,线圈内径为?20 mm,匝数为2,线圈1的位置因素7)1为34.5 mm,线圈2的位置因素7)2为64 mm,两线圈的间距为5.5 mm。(4)30CrMnSiNi2A钢材料组织性能与感应加热工艺参数关系研究结果表明:铅浴回火和感应回火式样基体组织形貌基本一致,其组织都是保持着回火马氏体的板条形貌,且板条上存在着碳化物析出,这为感应局部回火代替铅浴回火提供了组织可能;硬度分析表明,工件表面最大温度决定径向硬度分布,且表面温度范围在450℃-550℃间,硬度分布符合工艺要求;适当的保温(保温时间1-5 s)可以优化径向硬度分布。本文中,所选取的30CrMnSiNi2A螺纹件局部回火工艺参数为:电流频率f=120KHZ,电流密度Js=25 e6A m2?,加热时间为3 s,保温时间1-5 s。
[Abstract]:During the process of processing and heat treatment of 30CrMnSiNi2A ultra-high strength steel thread parts, the stress concentration is easily formed in the thread parts. It has become a trend to replace the backward lead bath tempering process with high frequency induction heating in the partial tempering of workpiece. The parameters of 30CrMnSiNi2A thread parts are determined by the combination of numerical simulation and experiment. It is very important to replace the traditional lead bath tempering technology with high efficiency induction heating system and to obtain 30CrMnSiNi2A thread parts with high comprehensive performance. In this paper, starting with the numerical simulation of electromagnetic temperature field of 30CrMnSiNi2A thread parts, a numerical calculation model suitable for the local tempering process of 30CrMnSiNi2A thread parts by induction heating is established. The influence of various process parameters on induction heating of 30CrMnSiNi2A steel was studied, and the optimum design of local tempering induction coil of 30CrMnSiNi2A steel small thread workpiece was carried out, and the relationship between the parameters of induction heating process and the microstructure and properties of 30CrMnSiNi2A steel material was also studied. Finally, the process parameters of induction partial tempering of 30CrMnSiNi2A steel thread workpiece are determined. Based on the experimental analysis, the following conclusions are obtained: (1) the modeling and analysis of the induction heating of 30CrMnSiNi2A steel workpiece, including the establishment of solid model, the thermo-physical parameter model of 30CrMnSiNi2A material, the mesh division of the solid model, the setting of boundary load conditions and the solution of loading. It is found that the numerical simulation results are similar to the experimental results, which has a certain guiding significance for practical operation. (2) during the induction heating process, the surface temperature of the workpiece reaches phase transition temperature rapidly. After maintaining a stable phase transition point, the temperature curve of the workpiece shows a different trend; the current density value is positively related to the magnitude of the inductive magnetic field intensity, which directly affects the final heating temperature; the current frequency will affect the penetration depth of the material. Furthermore, the temperature difference of the core after induction heating is affected. The high frequency can increase the surface temperature of the material and the thermal efficiency in a very short time, but the influence of the increase of the frequency in the high frequency stage is less and less obvious, so the choice of the frequency needs to be considered synthetically. The effect of coil thickness on induction temperature is the same as that of current density. The design of coil wall thickness is mainly considered from the power loss and economy of the inductor. (3) the local tempering induction coil of 30CrMnSiNi2A thread is optimized. The optimized coil is: the section of induction coil is rectangular, Rectangular section size 12 脳 6 mm, coil wall thickness 1 mm, coil inner diameter 20 mm, turn number 2, coil 1 position factor 7) 1 34.5 mm, coil 2 position factor 7) 2 64 mm, distance between two coils 5.5 mm. (4) Microstructure, properties and induction addition of 30CrMnSiNi2A steel The results of the study on the relationship of thermal process parameters show that the microstructure of the matrix is basically the same as that of the lead bath tempering and induction tempering. The microstructure of all of them is to maintain the lath morphology of tempered martensite, and the carbides precipitate on the lath, which provides the possibility for inductive partial tempering instead of lead bath tempering, and hardness analysis shows that, The maximum surface temperature of the workpiece determines the radial hardness distribution, and the surface temperature ranges from 450 鈩，
本文编号：2131590
[Abstract]:During the process of processing and heat treatment of 30CrMnSiNi2A ultra-high strength steel thread parts, the stress concentration is easily formed in the thread parts. It has become a trend to replace the backward lead bath tempering process with high frequency induction heating in the partial tempering of workpiece. The parameters of 30CrMnSiNi2A thread parts are determined by the combination of numerical simulation and experiment. It is very important to replace the traditional lead bath tempering technology with high efficiency induction heating system and to obtain 30CrMnSiNi2A thread parts with high comprehensive performance. In this paper, starting with the numerical simulation of electromagnetic temperature field of 30CrMnSiNi2A thread parts, a numerical calculation model suitable for the local tempering process of 30CrMnSiNi2A thread parts by induction heating is established. The influence of various process parameters on induction heating of 30CrMnSiNi2A steel was studied, and the optimum design of local tempering induction coil of 30CrMnSiNi2A steel small thread workpiece was carried out, and the relationship between the parameters of induction heating process and the microstructure and properties of 30CrMnSiNi2A steel material was also studied. Finally, the process parameters of induction partial tempering of 30CrMnSiNi2A steel thread workpiece are determined. Based on the experimental analysis, the following conclusions are obtained: (1) the modeling and analysis of the induction heating of 30CrMnSiNi2A steel workpiece, including the establishment of solid model, the thermo-physical parameter model of 30CrMnSiNi2A material, the mesh division of the solid model, the setting of boundary load conditions and the solution of loading. It is found that the numerical simulation results are similar to the experimental results, which has a certain guiding significance for practical operation. (2) during the induction heating process, the surface temperature of the workpiece reaches phase transition temperature rapidly. After maintaining a stable phase transition point, the temperature curve of the workpiece shows a different trend; the current density value is positively related to the magnitude of the inductive magnetic field intensity, which directly affects the final heating temperature; the current frequency will affect the penetration depth of the material. Furthermore, the temperature difference of the core after induction heating is affected. The high frequency can increase the surface temperature of the material and the thermal efficiency in a very short time, but the influence of the increase of the frequency in the high frequency stage is less and less obvious, so the choice of the frequency needs to be considered synthetically. The effect of coil thickness on induction temperature is the same as that of current density. The design of coil wall thickness is mainly considered from the power loss and economy of the inductor. (3) the local tempering induction coil of 30CrMnSiNi2A thread is optimized. The optimized coil is: the section of induction coil is rectangular, Rectangular section size 12 脳 6 mm, coil wall thickness 1 mm, coil inner diameter 20 mm, turn number 2, coil 1 position factor 7) 1 34.5 mm, coil 2 position factor 7) 2 64 mm, distance between two coils 5.5 mm. (4) Microstructure, properties and induction addition of 30CrMnSiNi2A steel The results of the study on the relationship of thermal process parameters show that the microstructure of the matrix is basically the same as that of the lead bath tempering and induction tempering. The microstructure of all of them is to maintain the lath morphology of tempered martensite, and the carbides precipitate on the lath, which provides the possibility for inductive partial tempering instead of lead bath tempering, and hardness analysis shows that, The maximum surface temperature of the workpiece determines the radial hardness distribution, and the surface temperature ranges from 450 鈩，
本文编号：2131590
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