In the pipe welding, a welding rod welding in the replacement of an electrode should be how to deal with joints?
1, if the strict requirements for pipeline welding, portable welder hammer medicine skin clean, in a welding rod arc welding joint has less to stay in the rear has deposited metal (no more than a centimeter can) for a moment, a swing, further the welding slag burn surface welding quality;2, in large long-distance pipeline, welding joints must be cleaned with a sand turbine, and then the next step of welding.
Pipeline welding joints, is most in need of careful treatment, whether it is single channel multi pass welding or welding, the joint processing is not good, there may be slag, poor fusion welding defects such as weld, resulting in leakage after completion of pressure test;There are two kinds of joint methods after replacing electrode:1 、 hot connection:After stopping quickly changed new electrode, is the ability to remain in the state at the arc, immediately from the pool in front of the arc and the arc pulled at the arc with the rapid arc even (horizontal zigzag) welding, welding to weld arc hole under pressure, a when arc melting groove blunt edge "puff" sound, immediately moved into normal welding method of welding;The main point is to replace the welding rod, the action should be quick, and the joint must be skilled and flexible. It is a commonly used joint method in welding production.2, cold connection:Cited the joint of the slag shall be clean at the arc arc, too high or have evidence to grinding in the gentle slope, and then from the original crater 10mm arc, with long arc slightly preheated with arc welding to the horizontal swing forward arc pit, arc under pressure, when the arc breakdown root hair a "Puff" sound after welding can be transferred to normal.Cold joint advantage is not good when the arc weld (with shrinkage or welding meat too thick), can eliminate the defects and grinding, thin joints, easy to ensure the welding quality; the difficulty is small heat connection; drawback is not as efficient as the thermal connection is high, especially not allowed in grinding joints, (such as skills competition) should not be used this method.
Welding slag to be removed, the new welding rod pressure on the bead welding, the new welding rod can be used arc lead arc welding
