窄间隙TIG横焊侧壁熔合行为

Investigation on sidewall fusion behavior of horizontal narrow gap TIG

开展了不同焊接工艺参数对窄间隙坡口上下侧壁熔合行为研究．结果表明，钨极位置对下侧壁的熔深影响比较显著，钨极位置在－1．5 mm到－2．5 mm时，焊缝成形比较稳定．其次是焊接电流对于下侧壁熔深影响较大，基值电流在150～250 A时下侧壁熔合良好．送丝速度和脉冲频率对于焊缝表面弯曲程度和夹角α影响较大，送丝速度增加至3000 mm／min之后，夹角α接近直角；脉冲频率大于10 Hz，焊缝表面弯曲程度变得很小，夹角α接近直角，以上两种情况严重影响下侧壁熔合．钨极位置和电弧电压对上侧壁熔合行为影响比较显著，钨极位置为1．5 mm时，上侧壁开始出现咬边现象．送丝速度增加至3000 mm／min时，焊缝与上侧壁的夹角开始变小．

Up and down narrow gap groove was separately studied. The results showed that,dowm sidewall fusion behavior:has the most obviously effects on down sidewall penetration depth,when the position of Tungsten electrode is between-1. 5mm and-2. 5 mm,and weld is relatively stable; the welding current also has a greater effect on down sidewall penetration depth,when the base current is between 150 A and 250 A,there is a good fusion,the wire feed speed and pulse frequency have a greater influence on the weld surface bending degree and angleα. When the wire feed speed is increasing to 3 000 mm /min,the angle α is close to the right angle; When the pulse frequency is greater than 10 Hz,the weld surface has a very small degree of curvature,and the angle α is close to the right angle,the above two cases seriously affect the up sidewall fusion. Up sidewall fusion behavior: the position of Tungsten electrode and the arc voltage effects on up sidewall fusion behavior obviously,when arc voltage is 16 V and the position of Tungsten electrode is 1. 5mm,the up sidewall begins to be appearance of undercut. wire feed speed is greater than 3 000 mm / min,bad welds and on the side wall of fusion.