The technique of overhand welding

1. Pad welding.Plate welding test plate Angle is 90 °, and the direction of the welding Angle is 70 ° ~ 80 °, the welding current is 120 a, broken arc welding method, the electrode in the welding groove of the transverse swing, slightly will preheat, electrode when the welding in the welding of the tail a little push rod, hear the sound of the "yue" said groove roots had melted, the original molten pool has been formed, in front of the molten pool, on both sides of the groove formed respectively 0.5 ~ 1 mm depth of melt hole, the electrodes under the syncline arc suppression, supported by arc blow force of iron liquid, will be part of the liquid iron to the back of the test plate,The center of the molten electrode in front of the new pool must be aligned with the front end of the pool and the boundary of the base metal, positioning the joint correctly each time. 

2. Filler welding.The Angle between filler electrode and welding direction is 85°~90°, and the welding current is between 100 °~ 120A. During filling welding, the spatter in front welding should be cleaned carefully, and the arc welding method should be adopted to carry out double and triple welding.Always start the arc 10~15 mm away from the welding pass, make the arc return to the original welding site for welding, welding using short arc sawtooth or crescent shaped electrode.When welding rod is swinging on both sides of groove, it stops a little, both sides are slow, the middle is fast, the molten pool remains elliptical, the welding path is flat, when welding the last filler welding pass, the groove edge is complete, its height is 1~2mm wide from the surface of the test plate,

3. Cover welding.The Angle between the welding electrode on the cover and the welding direction is 85°~90°, and the Angle between the test plates on both sides is 90°. The welding method of the cover is basically the same as that of the filling welding. When the welding electrode swings to the groove edge, it stops slightly.

 
Phos-Copper Brazing Alloy