共查询到20条相似文献,搜索用时 0 毫秒
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针对埋弧焊磁控电弧焊缝跟踪系统中磁控电弧传感器产生的外加横向磁场,文中采用有限元分析方法建立了由磁控电弧传感器产生的横向磁场计算模型.应用ANSYS软件对横向磁场进行了模拟;对该横向磁场的纵截面分布、磁流密度矢量的分布规律进行了仿真;并对模拟结果的偏差进行了分析.实际测试结果说明了磁感应强度模拟值与实测值的一致性.针对励磁电流对焊接电弧运动状态的影响进行了实际焊接试验.结果表明,焊接电弧随励磁电流的增大而摆动,且励磁电流越大电弧摆动幅度也越大. 相似文献
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针对活性剂等离子弧焊焊接过程,对焊接电弧外形的变化,焊接电弧电压与活性剂之间的关系进行了研究,采用红外热像伪着色法测定了活性剂等离子弧焊焊接电弧温度场,并建立了活性剂等离子弧焊焊接电弧热流密度径向分布模型.研究结果表明,活性剂等离子弧焊焊接电弧收缩,弧尾翼消失,尾焰加大,电弧穿透力增强,电弧电压升高;活性剂等离子弧焊焊接电弧的温度分布比较紧凑,温度场外形窄,温度分布范围较集中,电弧径向温度梯度较大;电弧径向温度分布呈现正态Gauss分布模式;使用活性剂后的焊接接头性能与未使用活性剂焊接接头相当. 相似文献
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A. D. Razmyshlyaev S. V. Yarmonov P. A. Vydmysh M. V. Ageeva 《Welding International》2016,30(6):463-466
The design of equipment for generating the transverse magnetic field in arc welding can be optimised by modelling the direct magnetic field produced by the device for generating (GD) the transverse magnetic field (TMF) by the electric field of the current flowing in flat models made of electrically conducting materials. The lines of force of the electric field in the flow of the current in the modelling medium correspond to the lines of force (induction lines) of the magnetic field generated by GD TMF. Using these modelling methods, it is shown that to obtain the maximum values of the transverse component of the induction of the magnetic field in the zone of the welding arc of the electrode droplet and liquid metal of the weld pool, the optimum design of GD TMF is the one in which the angle of inclination of the bars to the vertical is equal to 45° and the end surfaces have chamfers parallel to the plane of the welded sheets. 相似文献
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基于局部热平衡状态假设,建立外加高频纵向磁场作用下的钨极惰性气体保护焊的电弧稳态三维数值模型.通过对麦克斯韦方程组、连续性方程、动量守恒方程、能量守恒方程的耦合求解,得到了电弧的温度场、流场和压力场等计算结果.结合法拉第电磁感应定律,考虑时变磁场的电磁感应效应,引入感应电场,解释了高频纵向磁场作用下的电弧收缩现象.结果表明,外加高频纵向磁场感应产生环向电场,形成环向电流,环向电流与外加纵向磁场作用产生径向洛伦兹力,导致电弧收缩. 相似文献
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Yoshihiro Yamaguchi Yusuke Katada Takeru Itou Yoshihiko Uesugi Yasunori Tanaka Tatsuo Ishijima 《Welding International》2013,27(10):745-753
Oxygen plasma arc cutting (PAC) is widely used in various industrial fields. In the case of cutting magnetized plates, the magnetic field is concentrated around the cutting front according to the progress of the cutting, and the electromagnetic force induced by leakage magnetic field deflects the plasma jet. The deflected plasma jet causes poor cutting quality and sometimes causes fatal damage on the electrode and the nozzle by a double arc as abnormal discharge. This phenomenon is called magnetic arc blow, and it is a critical issue of applying plasma cutting on magnetized plates. The purpose of this study is to investigate the arc blow behaviour and to devise a method to prevent it. We examined the relationship between operating conditions and double arc with external magnetic fields on the plasma jet. We found criteria of operation conditions that induce the arc blow. In addition, we have succeeded in suppressing the double arc generation attributed to the external magnetic field with a mild steel shield cap attachment around the nozzle tip. 相似文献
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Aimed at plasma arc welding, a mathematic model was established according to the theory of magnetic fluid dynamics. The model was numerically analyzed by ANSYS software. The temperature, current density and plasma velocity distributions of normal arc had been simulated and compared with those of double arc. The results show that the appearance of double arc has made the temperature of the nozzle rise up to 5 000 K. The appearance of side arc could make the current density of the main arc decrease, and also make the maximal temperature of the arc reduce. 相似文献
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通过在低碳钢表面进行等离子弧堆焊时外加交流脉冲横向磁场,研究了交流脉冲磁场对镍基自熔合金组织及性能的影响,并利用光学金相、X射线衍射、显微硬度和湿砂橡胶轮磨损试验等方法,系统分析了不同脉冲磁场电流、占空比作用下的堆焊试样的硬度、耐磨性及组织.结果表明,外加横向交流脉冲磁场可以有效改善堆焊层金属的结晶形态,细化晶粒,在适当的脉冲磁场电流、占空比作用下,可以获得最佳的电磁搅拌效果,增加堆焊层金属中硬质相的数量,控制硬质相的生长方向,提高等离子弧堆焊层的硬度和耐磨性. 相似文献
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A new kind of control system for keyhole plasma arc welding (K-PAW) was developed based on the computer and the Graphics Language--LabVIEW. It can set and output the required current waveforms with desired decreasing slopes so that the corresponding "opening and closing" of keyhole can occur periodically. With this control strategy of welding current waveforms, the workpiece is fully penetrated while no burn-through Occurs. Keyhole plasma arc welding experiments were conducted to verify the stability and reliability of the developed system. 相似文献
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To improve the penetrating ability and the welding quality of keyhole plasma arc welding, a novel penetration closed-loop control system was established. In the system, welding current and plasma gas flow rate were selected as adjusting variables. The wavelet method was used to detect penetration status from welding arc voltage in real-time. The control strategy of one-keyhole-per-pulse was adapted to fulfill stable and high quality welding process. Experimental results show that the developed system can apparently increase the penetrating force of plasma arc and keyhole plasma arc welding is realized successfully in stainless steel with 10 mm in thickness. Moreover,the disturbances of gradual change and break change from 3mm to 6mm in thickness are come over due to the good response property of the developed system. 相似文献
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利用设计的轴向磁场产生装置,采用理论与试验相结合的思路,将其作用于非熔化极焊接过程,包括等离子焊接和钨极氩弧焊(TIG)两种焊接方法.利用高速摄像装置观察电弧形态变化,获得并对比两种电弧的变化情况.结果表明,由于等离子电弧本身组成的特殊性,导致其与TIG电弧在同样磁场作用下发生变化的程度不同.然后做出运动受力分析,建立了轴向磁场下的粒子运动模型,由于粒子轴向运动速度的差异性,导致轴向磁场下带电粒子的运动阶段的不同,给出了两者在磁场下不同变化的原因. 相似文献
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在镍基堆焊合金等离子弧堆焊过程中引入横向交流脉冲磁场,研究了横向交流脉冲磁场频率对等离子弧堆焊层金属组织及性能的影响,并利用光学金相、X射线衍射、显微硬度和湿砂橡胶轮磨损试验等方法,系统分析了不同脉冲磁场频率作用下堆焊试样的硬度、耐磨性及组织.结果表明,外加横向交流脉冲磁场可以有效改善堆焊层金属的结晶形态,细化晶粒,在适当的脉冲磁场频率作用下,可以获得最佳的电磁搅拌效果,增加堆焊层金属中硬质相的数量,控制硬质相的生长方向,提高等离子弧堆焊层的硬度和耐磨性. 相似文献
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以外加横向交变磁场作用下的等离子体弧为研究对象,建立了等离子体弧摆动幅度和热流密度分布的数学模型.对横向交变磁约束下的等离子体弧射流特性进行理论研究,并分析工艺参数和励磁强度对横向交变磁约束等离子体弧形态和特性的影响规律.结果表明,横向交变磁场可有效控制等离子体弧形态和位置,等离子体弧在横向交变磁场作用下,分布范围增大、热流密度梯度减小.其摆动幅度随磁场强度的增加而增大,但过高的磁场强度会使等离子体弧变得不稳定;相同励磁强度下,气流量和弧电流越小、喷嘴到工件的距离越大,则摆动幅度越大;而工件表面的等离子体弧热流密度分布随励磁强度的增强趋于平坦化;相同励磁条件下,热流密度峰值随气体流量和弧电流的增大而增大、随喷嘴到工件距离的增大而减小. 相似文献
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以单粒子理论假设为基础,详细阐述了外加纵向磁场在等离子体中的不均匀分布形态,以及这种不均匀磁场对TIG焊接电弧形状的影响,分析了电弧区的受力情况,建立了等离子体中带电粒子在这种非均匀磁场中的运动方程.由分析可知带电粒子在磁场作用下的运动轨迹是一条汇聚的螺旋线,且等离子弧外围的带电粒子的圆周运动的速度远大于弧柱中心的粒子运动速度.结果表明,在外加纵向磁场的作用下,TIG焊电弧发生了明显的收缩,激磁电流一定,激磁频率越高,电弧收缩越明显. 相似文献
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采用"高斯+双椭球"热源模型,建立正、反极性等离子电弧热源模型。采用APDL(ANSYS parametric design language)编程语言,对变极性等离子弧焊(VPPA)温度场进行模拟。通过分析其温度场,计算出正、反极性等离子弧焊高温区面积和熔池形状,并通过实际焊接试验验证了该模型的合理性,这为焊接工艺参数的合理选择提供了理论依据。 相似文献
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以直流TIG焊接电弧为对象,依据磁流体动力学理论构建电弧的数学模型,运用ANSYS有限元分析软件对二维稳态下轴对称的、氮氩混合气体保护的TIG焊接电弧进行了数值分析,得到了ψ(N2)50% Ar混合气体保护下焊接电弧的温度场、速度场的形态分布特征.分析表明,氮氩电弧的最高温度出现在近阳极区域,电流密度、等离子体速度和电弧压力的最大值均出现在近阴极区.同时分析了不同电流、弧长对阳极表面电流密度的分布的影响,随着电流的增大,阳极表面电流密度增大,而随着弧长的增大,电流密度减小. 相似文献