新型柔性变极性等离子弧铝合金横焊技术研究

发布时间：2018-06-03 15:15

本文选题：铝合金 + 横焊　；参考：《机械工程学报》2015年24期

【摘要】：针对中厚板铝合金横向焊接的技术需求和瓶颈问题,开展变极性等离子弧穿孔横焊技术的研究。以8 mm厚铝合金板为研究对象,进行常规变极性等离子弧穿孔横焊试验,发现横焊穿孔熔池很难建立。通过横焊穿孔熔池受力计算、熔化金属流动分析,探究问题产生的原因。推导出熔池背面小孔临界半径与表面张力、电弧力和重力之间的关系式。当受力状态满足关系式时,小孔熔池才能闭合、形成焊缝。依据上述理论,提出柔性变极性等离子弧。该电弧在保证穿孔前提下,通过降低电弧压力,增大小孔临界半径,促进了穿孔熔池的稳定建立。利用该技术实现了8 mm板厚2219铝合金的穿孔横向焊接,接头成形优良。焊前预热和表面氧化膜刮削可大幅度降低横焊接头气孔缺陷。
[Abstract]:Aiming at the technical requirement and bottleneck of transverse welding of medium and thick plate aluminum alloy, the research of variable polarity plasma arc perforation transverse welding technology is carried out. Taking 8 mm thick aluminum alloy plate as the research object, the experiment of conventional variable polarity plasma arc perforation transverse welding is carried out, and it is found that the weld pool of cross welding perforation is very difficult to establish. By calculating the force in the weld pool and analyzing the flow of molten metal, the cause of the problem is explored. The relationship between critical radius and surface tension, arc force and gravity is derived. When the stress state satisfies the relationship, the weld pool can be closed and the weld seam can be formed. According to the above theory, flexible variable polarity plasma arc is proposed. The arc can reduce the arc pressure and increase the critical radius of the hole to promote the stable establishment of the perforation pool. The perforated transverse welding of 2219 aluminum alloy with 8 mm plate thickness is realized by this technology, and the joint is well formed. Preheating before welding and scraping of surface oxide film can greatly reduce the hole defect of the transverse welded joint.
【作者单位】：哈尔滨工业大学先进焊接与连接国家重点实验室;首都航天机械公司;
【基金】：国家自然科学基金资助项目(51475105)
【分类号】：TG456.2

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