【作者】 曹梅青；

【导师】 邹增大；

【作者基本信息】 山东大学 ， 材料加工工程， 2006， 博士

【摘要】 双丝间接电弧气体保护焊是一种焊接时工件不接电源，电弧在两焊丝端部燃烧的新的焊接方法，主要利用熔滴携带热量和少量弧柱热量熔化母材形成焊缝。该方法具有热输入调节范围大、熔合比可降到最小、熔敷速度高、电能利用率高、焊接应力和变形小等特点，是一种优质、高效、节能的焊接方法，具有理论研究价值和应用前景。 本文利用自制的自动焊装置、FASTCAMSuper-10KC型高速摄像系统和Agilent54624A示波器等设备对双丝间接电弧Ar气和CO₂气体保护焊电弧稳定燃烧的条件、焊接工艺性、电弧形态及熔滴过渡进行了分析研究。 双丝间接电弧气体保护焊采用直流电源，双丝分别接电源两极，电弧在双丝间端部形成。由于电弧的正、负极的产热量不同将导致双丝熔化速度不相等，采用一种电弧控制系统同时控制双丝的送丝，则双丝将获得同样的送丝速度，不会得到稳定燃烧的电弧。本文选用NBC-350型逆变式焊接电源，系等速送进电弧自身调节，本研究采用两套控制系统来分别控制正、负极送丝，初始研究表明，负极熔化速度快，本文采用NBC-350电源的等速送进控制系统控制负极送丝机构。研究自行设计晶闸管调速电路控制系统调整控制正极的送丝机构。本研究表明，双丝间接电弧对双丝均有一定的自身调节作用。采取上述两套控制系统加之双丝间接电弧对双丝的自身调节作用，可使双丝间接电弧气体保护焊两极的送丝速度分别等于各自的熔化速度获得稳定燃烧的间接电弧。 焊枪集气、电、丝于一体，是双丝间接电弧气体保护焊的一个关键部分，焊枪的结构形状与几何尺寸不仅关系到其自身的使用性能，而且关系到电弧稳定性、气体保护效果和焊接质量等。双丝间接电弧焊焊枪中双丝之间的夹角直接影响到双焊丝对中性、焊枪长度、熔滴过渡形态、气体保护效果、电弧燃烧稳定性、焊缝成形及焊接过程的可达性和方便观察熔池。本文在实验研究与综合分析的基础上确定焊枪中双丝夹角为35°。双丝经过的导电嘴之间应相互绝缘，气筛设计选用绝缘板上均匀开小孔，使静气室内的保护气体可均匀地进入保护区。焊枪上的喷嘴用陶瓷喷嘴，既绝缘又耐高温。 焊接工艺参数对电弧燃烧稳定性、焊缝成形、焊接质量及焊接效率都有重要更多还原

【Abstract】 Twin-wire indirect arc gas shielded welding is a novelty welding technology, which work-piece is not linked to power source, arc is ignited and burns between the two wires, heat energy from arc column and droplets are used to melt work-piece. The advantages of this technology are large regulating range of heat input, minimum penetration ratio, high deposition rate, high usage of electric energy and low welding deformation and stress. It is a kind of welding method with high quality, high efficiency and energy conservation. It has extensive application foreground. In this paper, the welding procedure, arc characteristic and metal transfer behavior of twin-wire indirect arc gas shielded welding have been investigated systematically. The condition of stable arc burning, welding processing property, arc shape and metal transfer have been analysed by means of the automatic welding device (home-made), high-speed camera system (FASCAM Super-10KC) and oscilloscope (Aglient54624A) etc.The two wires linked to the two-pole of DC power source(NBC-350). thus the arc generates between the two wires. Different heat input leads to different melting rate, if using the same controlling systems, the melting rate of the two pole will be equal to each other, which lead to astable arc. Two different type of wire-feeding control systems were used in order to obtain the wire-feeding speed equal to the melting rate, and for obtaining stable burning arc, the two wire-feeing systems must match to each other. Results indicate that indirect arc can self-regulate, and the welding arc can burn stably in twin-wire indirect arc gas shielded welding.The welding gun is a key component of twin-wire indirect arc gas shielded welding. The structural shape and geometry dimension of welding gun not only relate to the service performance, but also relate to arc stablilyty, preservation of gas and welding quality. A special welding gun was developed. It is found that the angel of更多还原