焊接电流对双丝间接电弧焊电弧特性的影响

主要研究了焊丝伸出长度对焊接电流、电弧电压以及焊接电流对双丝问接电弧气体保护焊电弧特性的影响。结果表明,随着焊丝伸出长度的增加,焊接电流减小;双丝间接电弧气体保护焊负极焊丝的熔化速度随着焊接电流的增加而明显增大,正极焊丝的熔化速度随焊接电流的增加而缓慢增大,两者均随着电弧电压的增加而减小;随着焊接电流的增大熔滴变细;双丝问接电弧气体保护焊有多种电弧形态。     

双丝间接电弧氩弧焊的熔滴过渡

采用氙灯背光高速摄像系统及示波器对双丝间接电弧氩气保护焊的熔滴过渡及其对应的电压、电流波形进行了研究.结果表明,双丝间接电弧氩弧焊焊接电流与电弧电压的不同匹配选择,熔滴具有短路过渡、大滴过渡、混合过渡、射滴过渡、射流过渡等不同过渡形式.随着焊接电流的增大熔滴尺寸减小,熔滴细化,随电弧电压的增大,熔滴尺寸减小.熔滴过渡形式与电压、电流的波形之间有很好的对应关系.     

三丝间接电弧焊电弧形态及焊缝成形分析

气体保护三丝间接电弧焊是一种新型的焊接方法，电弧建立在主丝与边丝之间，工件不连接电源.文中建立了稳定的三丝间接电弧，针对焊缝侧壁熔合问题，分析了不同焊丝分布方式产生的电弧形态对侧壁熔合的影响；针对焊缝层间熔合问题，采用后置钨极的方法实现了焊缝层间熔合.结果表明，主丝与边丝送丝速度与熔化速度相匹配，可建立稳定的三丝间接电弧；焊丝分布Ⅳ沿焊接方向的电弧偏向两侧壁，垂直于焊接方向的电弧形态集中，电弧稳定性好，可实现焊缝侧壁均匀熔合，熔合深度为1~1.2 mm；施加后置钨极，可实现焊缝层间熔合，焊缝抗拉强度为420 MPa，断裂位置发生在母材.     

脉冲频率对三丝间接电弧焊稳定性的影响

三丝间接电弧焊是一种新的焊接方法,焊接过程中工件不连接电源,主丝连接焊接电源正极,两边丝分别连接两焊接电源的负极,电弧建立在主丝与两边丝之间. 焊丝熔化后主丝与边丝导电距离的变化以及焊丝形成的多条熔滴过渡路径均对建立稳定的焊接过程提出了挑战. 文中通过调控脉冲频率,分析了脉冲频率对电弧特性、熔滴过渡路径以及焊接电压和焊接电流分布的影响. 结果表明,脉冲频率对三丝间接电弧焊的稳定性影响较大,当脉冲频率大于100 Hz时,才能建立稳定的间接电弧;随着脉冲频率的增加,熔滴过渡路径的数量减少,更有利于形成均一的焊道;随着脉冲频率的增加,焊接电压和焊接电流变异系数减小,焊接电流和焊接电压的波动程度减小,三丝间接电弧焊的稳定性提高.     

SACTIG与VPTIG电弧稳定性的对比分析(二)

利用高速录像系统、焊接电弧测试分析仪同步实时采集正弦交流TIG(SACTIG)和变极性TIG(VPTIG)焊接电流、电弧电压、电弧形态信息,以再引弧过程中两电极空间气体的平均电导变化率为判据,建立了VPTIG电弧稳定性数学模型;比较分析了SACTIG与VPTIG焊接电流过零期间,焊接电弧稳定性与相关电学参数之间的关系.试验表明,VPTIG与SACTIG电弧本质上同属ACTIG电弧,虽然两者相关电学参数对电弧稳定性影响的规律方面是一致的;但是VPTIG与SACTIG电弧在产热、散热、极性转变特性、焊接电源空载电压、焊接电流波形等方面存在差别,两者电弧稳定性表现出许多不同特点.VPTIG和SACTIG焊接电弧稳定性分别随VPTIG焊接电源施加在两电极之间空载电压的上升斜率和SACTIG电源空载电压频率增大而提高;再引弧电压Ur越高电弧越不稳定;焊接电源空载电压越高电弧越稳定;焊接电流越大电弧越稳定.     

熔化极气体保护焊电流与电压调节

在应用熔化极气体保护焊的基础上,分析焊接电流和电弧电压对焊缝成形的影响,探究焊接电流与电弧电压匹配对焊接电弧特性的影响规律,总结正确调节焊接电流与电弧电压的基本方法和操作技能,正确调节焊接电流与电弧电压是熔化极气体保护焊技术推广与应用的关键因素。     

低碳钢双丝气体保护焊工艺设计

双丝气体保护焊是一种高效化焊接方法,能够在保证焊接质量的前提下进行高速焊接。本文基于焊接机器人系统,研究了焊接电流、电压和速度对电弧稳定性、飞溅、焊缝成形及微观组织的影响规律,并改进双丝焊工艺。研究结果表明:控制前丝与后丝焊接电流、电弧电压的差值在一定范围内可实现1.2 m/min高效稳定焊接,但当焊接速度进一步提高时会影响焊接质量。优化后的焊接工艺方案:前丝焊接电流260 A、后丝焊接电流240 A、前丝电弧电压24.7 V、后丝电弧电压23.9 V、焊接速度1 m/min。     

双丝串列电弧焊焊缝成形的试验分析

将旋转电弧传感器和双丝串列电弧焊结合起来,开发了旋转电弧引导的、两个电弧在同一个熔池上燃烧的双丝串列电弧焊方法,对其焊缝成形工艺进行了研究.分析了焊接电流、焊接电压、双丝间距、电弧旋转等参数对焊缝成形的影响.结果表明,随着焊接电流的增大,熔敷速度增加,焊缝成形系数呈现先增大后减少的变化规律.而焊接电压的增大则会使焊缝成形系数略有减小.对双丝间距的研究发现,当间距为15 mm时,焊接质量较好.与普通双丝串列焊相比,前置电弧旋转时熔池底部变得平坦,最大熔深有所减小,平均熔深有所增加,这将有助于减少焊缝的应力集中.与单丝旋转电弧焊相比,焊接熔敷速度显著增大,有效避免了高速焊接时的咬边现象.     

双丝脉冲MAG焊不同外特性组合下的工艺试验

提出2种比较适合脉冲焊外特性的组合方式,即U-I和I-I.结合双丝焊电源外特性组合方式的理论分析,系统地进行了主从机的3种典型外特性组合的工艺试验,并总结出了双丝焊电源焊接电流、电弧电压分布的一般规律,即主机电流约大于从机电流20～30A,从机电压约高于主机电压2V.通过试验,加深了对双丝焊电弧间热作用、双丝焊工艺特点以及不同外特性组合优缺点的认识.     

自保护药芯焊丝激光—电弧复合热源焊接电弧稳定性的分析

以自保护药芯焊丝（414N-O）为研究对象,借助电弧分析仪和高速摄像,对不同工艺参数下激光—电弧复合热源焊接电弧稳定性进行了试验研究.结果表明,复合热源焊接过程中,激光的加入明显的减小了自保护药芯焊丝电弧作用点漂移概率,拉长了电弧空间,降低了熔滴短路过渡概率,提高了电弧稳定性;工艺参数中,光丝间距和送丝速度对平均焊接电流影响显著;电弧电压和送丝速度对平均焊接电流变异系数影响显著;激光功率对平均焊接电流的影响幅度与光丝间距和送丝速度有关,光丝间距和送丝速度越大,激光功率对平均焊接电流的影响越小;电弧电压对平均焊接电流的影响幅度与光丝间距有关,光丝间距D_LA=0 mm时,影响最显著;激光前置比激光后置更有利于平均焊接电流变异系的稳定.     

旋转电弧双丝串列焊焊缝跟踪

从时域波形、统计特征、自相关特性以及互相关特性等方面分析了旋转电弧双丝串列焊焊接电流的变化规律.结果声明,当空载电流增大时,前置焊丝上的焊接电流成正弦波动,并具有明显的自相关特性,表明空载电流的增大有助于提高电弧传感的灵敏度,但同时前后焊丝上的焊接电流互相关系数变大,说明二者相互影响增加.当空载电压增大时,电弧的挺度增加,前置焊丝上的焊接电流正弦波动变小,电弧传感的灵敏度变差.设计了软阈值小波滤波算法和分段参数自调整模糊控制算法,实现了双丝串列焊水平弯曲角焊缝跟踪,焊接速度达到90 cm/min.     

Twin-wire indirect arc welding by modeling and experiment

Argon-shielded twin-wire indirect arc (TWIA) welding is a method with a high melting rate, high welding efficiency, low welding deformation and low penetration depth of the weld joint. In this paper, the arc behavior of the twin-wire indirect arc (TWIA) for current values of 100 A, 150 A and 200 A and their influence on the welding process were discussed, and the reasons of the previously mentioned advantages of this welding method were analyzed. The plasma temperature was measured to verify the correctness of the simulation. The results indicate that the arc behavior is mainly controlled by the welding current. With the increasing current, the arc parameters in the anode and cathode regions significantly increase, whereas those in the arc column region vary by a smaller degree. The rate of increase of the arc parameters in the entire arc region is smaller than that of the welding current. The isotherm shifts toward the anode side and the shift of the isotherm increases when the welding current increases. The advantaged of TWIA welding was discussed according to the calculated result.     

单电源双丝埋弧自动焊研究

单电源双丝埋弧自动焊是一种高熔敷速率、高焊接速度、低热输入的埋孤焊方法.通过改变焊丝排列方式和丝间距,其焊缝成形、熔深/熔宽、稀释率可得到更充分的调节.既可适用于稀释率要求较低的耐磨或耐腐蚀表面的埋弧堆焊,亦可适用于各种对接、角接焊缝的单道或多道高速埋孤焊.简述了这种焊机的结构要点,指出了电源及送丝系统的合理配置要求.     

Metal transfer and arc behaviour of novel consumable and non-consumable electrode indirect arc droplet welding

Abstract

The consumable and non-consumable electrode indirect arc droplet welding is a novel method that applies an indirect arc generated between a consumable electrode and a non-consumable electrode to welding. It was successfully used to overlap join the thin zinc coated steel plate. In the point to point (consumable electrode and non-consumable electrode) configuration, the stable metal transfer was obtained. The globular, projected spray and streaming spray transfer modes were promoted. With the increase in welding power, the metal transfer became faster and more stable. At the same time, the indirect arc became brighter, smaller and more stable. The arc self-regulation guaranteed the stable burning of the indirect arc. The desire stability was observed from the fluctuation of the welding current and the arc voltage waveforms. The side concentrated melting on the root of the droplet produced high pinch effect, which facilitated the detachment of the droplet.     

A computer-based control system for keyhole plasma arc welding

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.     

Arc characteristics of twin-wire indirect arc gas shielded welding

Twin-wire indirect arc gas shielded welding is a novel welding method. By recording the arc shape and welding parameters, the effects of welding parameters and included angle on arc characteristics are discussed in this paper. The experimental results show increasing welding current can prompt centralized and straight of arc due to increasing plasma force and electric magnetic pinch effect. Increasing arc voltage can increase the size and brightness of the arc, as a result of increasing arc energy. The reducing of included angle increases the electric magnetic pinch effect, the arc becomes slender and supplies higher energy. It is thought the smaller included angle is beneficial to obtain perfect weld bead.     

磁场对双丝间接电弧形态的影响

对双丝间接电弧在自身磁场及外加磁场变化的情况下,电弧形态随磁感应强度值的变化规律进行了研究.自身磁场变化通过改变两焊丝夹角角度实现,外加磁场由励磁线圈产生,对间接电弧施加横向及纵向磁场,磁场强度利用特斯拉计测出,并借助高速摄像系统对磁场变化时的电弧形态进行拍摄.研究表明,通过改变两焊丝夹角及施加横向磁场的方式,可使两焊丝所夹区域内外磁场强度之差变大,使得电磁力的外扩作用增大,电弧变细长;施加纵向磁场时,电弧在与两焊丝垂直的平面内发生偏转,其偏转程度随纵向磁场强度增加而增加.