交叉耦合电弧焊接方法及热力传输机制研究

发布时间：2018-03-25 19:13

本文选题：交叉耦合电弧焊　切入点：绕弧行为　出处：《北京工业大学》2016年博士论文

【摘要】：交叉耦合电弧焊接方法作为一种新型的高效焊接方法,将非熔化极电弧(GTA或PA)和熔化极电弧交叉耦合,非熔化极电弧在电极和工件之间燃弧,主要决定工件的热输入、熔滴和熔池的力输入,熔化极电弧在两根焊丝之间燃弧,与工件之间没有电的联系,主要控制金属的熔敷和部分工件的热输入。交叉耦合电弧的非熔化极电弧和熔化极电弧焊接规范参数可以单独调整,实现了工件热输入、金属熔敷和电弧力的解耦控制,可根据焊缝的需求,调整焊接规范得到理想的焊缝,为实现优质高效电弧焊接提供新的技术手段。为了深入研究交叉耦合电弧焊接方法的电弧耦合特性、电弧行为和熔滴过渡机理,本课题针对交叉耦合电弧焊接方法,在其成弧原理、电弧行为、熔滴受力分析和熔滴过渡行为方面展开研究:(1)对交叉耦合电弧成弧原理及特点进行研究。针对交叉耦合电弧多参数和焊接过程的复杂性,以等离子弧焊接电源、双丝间接电弧焊接电源和交叉耦合电弧同步控制器为硬件基础,搭建了交叉耦合电弧焊接电源系统,实现了等离子电弧和丝间电弧的协调控制。搭建了交叉耦合电弧高速影像采集分析系统和电弧力测量系统,为后续交叉耦合电弧焊电弧行为和熔滴过渡行为的实验研究提供了良好的硬件平台。交叉耦合电弧焊接方法中主电弧和丝间电弧独立调整的工作模式,改变了传统电弧在金属熔敷和焊接热输入固有的搭配,实现焊接过程中的传热、传力和传质的解耦控制。通过调整交叉耦合电弧焊的工艺参数可实现高熔敷量焊接和焊缝成形可控的焊接工艺。(2)对多电极耦合电弧行为进行研究。针对多电极耦合电弧焊接方法中不同的电弧耦合方式以及多参数的特点,通过交叉耦合电弧高速影像采集分析系统,采用电弧形态和电弧电信号同步分析的方法,分析了多电极耦合电弧的行为特性,实验发现多电极耦合电弧存在绕弧行为,这一特性改变了熔滴受力状态和电弧热量分布,结合电场和磁场的理论揭示了绕弧行为的本质。交叉耦合电弧焊接方法中,主电弧在丝间电弧磁场的作用下有规律地左右摆动,主电弧偏移至丝间电弧的阴极。旁路耦合电弧GMAW焊实验中,旁路电弧受到主电弧磁场的影响发生弯曲偏移,甚至直接建立在钨极和工件之间。旁路熔丝耦合电弧焊实验中,旁路电弧在主电弧磁场的影响下稳定的“绕行”钨极。(3)对交叉耦合电弧熔滴受力状态进行研究。交叉耦合电弧焊接方法中主电弧存在绕弧行为,改变了熔滴上作用力的方向、大小、数量,针对交叉耦合电弧焊中熔滴受力的复杂性,对熔滴受力的状态进行分析,研究发现,主电弧力对熔滴过渡有促进作用,促使熔滴脱离焊丝过渡至熔池中。交叉耦合电弧焊方法中主电弧(等离子电弧)对熔滴的作用力分解为两部分:一是等离子体对熔滴的冲击力,二是电弧自身对熔滴的推力,分别从两方面对主电弧(等离子电弧)的电弧力进行推导,建立交叉耦合电弧焊主电弧(等离子电弧)力的计算公式。(4)焊接参数对熔滴过渡行为影响。交叉耦合电弧熔滴过渡方式不同于传统熔滴过渡方式,影响熔滴过渡稳定性的工艺参数众多。实验研究等离子电弧的脉冲时间、峰值电流、离子气流量和脉冲频率等参数对熔滴过渡过程的影响规律,并确定熔滴过渡过程的稳定参数。
[Abstract]:The cross coupling method of arc welding as a high-efficient welding method model, the non consumable arc (GTA or PA) and MIG arc cross coupling, non consumable arc between the electrode and the workpiece arc heat input, the main decision of the workpiece, the droplet and molten pool of the power input, MIG arc in two the wire between the arc, no electrical contact between the workpiece and the heat input, main control metal cladding and part of the workpiece. The cross coupling arc non consumable arc and MIG arc welding parameters can be adjusted separately, the heat input decoupling metal cladding and arc force control, according to the weld needs, adjust the welding specification to get ideal weld, providing a new technical method for realizing high efficient arc welding arc. In order to study the coupling characteristics of cross coupling arc welding method, arc and droplet transfer behavior Through the mechanism, the topic for the cross coupling arc welding method, arc behavior in the arc principle, force analysis of droplet and droplet transfer behavior are studied: (1) the cross coupled arc arc principle and characteristics were studied. Aiming at the complexity of cross coupling and multi parameter of arc welding process, with plasma arc welding, twin wire indirect arc welding power source and arc cross coupling synchronization controller for basic hardware, build a welding power supply system with cross coupling arc, to realize the coordinated control of plasma arc and arc wire. Set up a cross coupled arc high-speed image acquisition and analysis system and arc force measuring system, provides a good hardware platform experiment for subsequent research on cross coupled electric arc welding arc behavior and droplet transfer behavior. The cross coupling arc welding method in the main working mode of arc and wire arc independent adjustment Type, change the traditional arc in metal cladding and welding heat input inherent collocation, achieve heat transfer in welding process, decoupling force transmission and mass transfer control. The welding technology to achieve high quality welding weld and weld formation can be controlled by adjusting process parameters of cross coupled electric arc welding. (2) the study of multi electrode coupled arc behavior. For multi electrode coupling arc welding method in different arc coupling mode and characteristics of multi parameters, through systematic analysis of cross coupled arc high-speed image acquisition, using the method of simultaneous analysis of arc shape and arc signal, analyzes the behavior characteristics of multi electrode coupling arc, the multi electrode coupling arc around the characteristics of arc behavior, change the droplet stress state and arc heat distribution, combined with the electric field and magnetic field theory to reveal the nature around the arc behavior. Cross coupling arc welding In the method, the main arc regularly in the wire between the arc magnetic field to swing, the main cathode arc deflection to wire arc. Bypass coupling arc GMAW welding experiment, the main effect of bypass arc by arc magnetic field bend offset, even directly established in between tungsten electrode and the workpiece. The bypass coupling arc fuse in the experiment, the main effect of bypass arc in arc magnetic field under the stable "orbiting" tungsten. (3) research status on stress of cross coupled arc droplet. Cross coupling arc welding arc the main methods in winding arc behavior, change the droplet on the direction of the force, size, number, according to the complexity by the cross coupling force of droplet in arc welding, the droplet stress state is analyzed, the study found that the main arc force to promote the role of droplet transfer, the droplet detachment wire transition to the molten pool. The cross coupled electric arc welding method The main arc (ARC) force of droplet is decomposed into two parts: one is the impact on the droplet plasma arc's two is on the droplet thrust, respectively from the two aspects of the main arc (ARC) arc force is deduced, the establishment of cross coupling arc welding and arc (ARC) the calculation formula of force. (4) the influence of welding parameters on the droplet transfer behavior. The cross coupling arc droplet transfer mode is different from the traditional mode of droplet transfer, many process parameters influencing the stability of droplet transfer. Experimental study on plasma arc pulse time, peak current, influence of plasma gas flow and pulse frequency parameters the droplet transfer process, and determine the stability parameters of droplet transfer process.

【学位授予单位】：北京工业大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：TG444

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