大直径钢螺柱新型焊接方法工艺研究

发布时间：2018-06-06 04:11

本文选题：螺柱焊 + 焊接成形　；参考：《南京理工大学》2017年硕士论文

【摘要】：本文主要解决关于22SiMn2TiB中碳调质高强钢与中大直径Q235实心螺柱之间的焊接缺陷问题,螺柱焊焊接方式的特点及高强钢母材的特性导致焊接过程中容易出现焊缝外观凸台不成形及焊缝气孔问题。针对于这些缺陷提出了大直径钢螺柱新型焊接方式:旋弧螺柱焊接方法、Cu铝热反应及Fe铝热反应-电弧螺柱焊接方法。焊接过程中的焊接电源接入选用型号为BMH-22SV拉弧式螺柱焊机,进行大量的探索性实验并合理规划工艺实验路线,改善装甲车等大型车辆的机械性能。旋弧装置可以有效的控制焊接电弧的运动轨迹,形成优质的焊缝外观成形,对于18mm直径的螺柱,焊接接头最大强度时的最佳焊接参数:旋弧装置输入电流为0.4A,焊接电源输入电流及拉弧时间分别为1250A,1200ms。旋弧焊接实心螺柱的缺陷是中心会出现一个孔,导致其焊缝力学性能不能达到最大值。Cu铝热反应-拉弧螺柱焊焊接方法可以有效地解决旋弧焊接的缺陷问题,焊缝熔池的液态金属流动性得到增强,因为铝热反应的热量使焊接热输入总和增加,形成完整的外观凸台及解决焊缝未熔合问题,对于18mm直径的螺柱,Cu铝热反应-拉弧螺柱焊最佳工艺参数:Cu铝热反应剂添加量为2.2g,焊接电源电流接入数值及焊接拉弧时间分别为1200A,1200ms,此参数下的焊接接头强度达到216MPa。Cu铝热反应-拉弧螺柱焊焊接方法缺陷是金相微观组织焊缝出现裂纹,贯穿整个焊缝,并向热影响区延伸。针对于Cu铝热反应-拉弧螺柱焊的缺陷,南京理工大学王克鸿老师团队提出Fe铝热反应-拉弧螺柱焊焊接方法对其进行优化设计,解决外观凸台成形不良、接头气孔及焊缝未熔合等缺陷。反应剂的添加量直接影响焊接质量,对于Φ18mm钢螺柱的最佳焊接参数:Fe铝热反应剂添加量为2.4g,拉弧式螺柱焊机输入电流值及焊接时间分别为1250A,1200ms,焊接接头抗剪强度达到307MPa。
[Abstract]:This paper mainly deals with the welding defects between 22SiMn2TiB medium carbon quenched high strength steel and medium and large diameter Q235 solid studs. The characteristics of stud welding and the characteristics of high strength steel base metal lead to the appearance of bevel and the problem of weld blowhole in welding process. Aiming at these defects, a new welding method of large-diameter steel stud is put forward, that is, the welding method of rotary arc stud and Fe aluminothermic reaction-arc stud welding method. In the welding process, the welding power supply is selected as BMH-22SV pull-arc stud welding machine. A large number of exploratory experiments are carried out and the technological experimental route is reasonably planned to improve the mechanical properties of large vehicles such as armored vehicles. The rotating arc device can effectively control the welding arc movement track, forming high-quality weld appearance, for the 18mm diameter stud, The optimum welding parameters are as follows: the input current of the rotary arc device is 0.4A, the input current of the welding power source and the time of arc pulling are 1250An 1200msrespectively. The defect of solid stud in spiral arc welding is that there will be a hole in the center, which leads to the failure to reach the maximum value of the mechanical properties of weld. The welding method of thermo reaction-pull stud welding can effectively solve the defect problem of spiral arc welding. The fluidity of liquid metal in the weld pool is enhanced because the heat of the thermal reaction increases the summation of the welding heat input, forms a complete appearance bump and solves the problem of the weld being not fused. For 18mm diameter, the optimum technological parameter of thermomechanical reaction-arc stud welding is 2.2g. the welding power current input value and welding arc drawing time are 1200An 1200msrespectively. The welding joint strength under this parameter is up to 1.2g. the welding strength of the welding joint under this parameter is up to 1 200 ms. the welding current input value and the welding arc drawing time are 1 200 ms. respectively. The defects of 216MPa.Cu thermal-reaction-arc stud welding method are the crack of metallographic microstructure weld. It runs through the weld and extends to the heat affected zone. Aiming at the defects of Cu thermal reaction-arc stud welding, the teacher Wang Kehong of Nanjing University of Science and Technology put forward a method to optimize the design of Fe aluminothermic reaction-arc stud welding to solve the problem of forming bad appearance bevel. Joint porosity and weld failure to fuse and other defects. The addition of reactants directly affects the welding quality. For 桅 18mm steel studs, the optimum welding parameter: Fe thermistor is 2.4 g, the input current value and welding time are 1250A1200msand the shear strength of welded joints is 307MPa.
【学位授予单位】：南京理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG457.11

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