双电极焊条单弧焊的熔化特性Ⅰ.双电极焊条的加热和熔化

Melting characteristic of twin electrode single arc welding I.Heating and melting of twin electrode

关键词:  双电极焊条  单弧焊工艺  加热和熔化  电阻热  电弧热

Key words:  twin electrode  single arc welding  heating and melting  electrical resistance heat  arc heat

摘要:

通过测量双电极焊条的动态温升等试验方法研究了双电极焊条单弧焊中双电极焊条的加热和熔化。研究结果表明,双电极焊条的熔化系数随焊接电流的增大、药皮重量系数和焊芯间距的减小而增大,是单芯焊条的2~3倍。加热和熔化双电极焊条的能量有焦耳效应产生的电阻热、电弧通过熔滴传给焊条端部的热;焊条的熔化主要依靠电弧的热量。在焊接终了时,随焊接电流增大,焊芯温度升高增大;对于200 A的焊接电流,TE4303焊条的温度升高到750 K以上;TE308-16焊条具有更大的温升和更快的熔化速度。电弧热在焊条上所形成的温度场一般集中在焊条燃烧的端部16 mm以内。由于电阻热的作用,焊接终了时的熔化速度比焊接开始时快了约20%。

Abstract:

With measuring dynamic temperature change of twin electrode,the heating and melting of twin electrode single arc welding was investigated.Results show that the melting coefficient of twin electrode increases with increasing of welding current,decreasing of coating weight coefficient and decreasing of two-core span,and it is 2-3 times than that of single core electrode.During twin electrode single arc welding,the energy used for heating and melting twin electrode includes resistance heat in core rod and arc heat.The melting of the electrode mainly depends on the arc heat.When the electrode was closely used up,for the current of 200 A,the increase in temperature of TE4303 electrode was approximately 750℃.TE308-16 electrode had high temperature evolution and fast melting rate.The range of temperature field generated by the arc heat in an electrode is generally within 16mm from the electrode end.