Welding technique for horizontal and overhead planes. Welding joints in positions other than the lower one, requires more skill welder due to possible under the influence of gravity outflow of molten metal from the weld pool and electrode metal droplets falling past the weld pool. To prevent this, welding should be carried out on the opportunities of the shortest arc in most cases, the transverse vibrations.
The molten metal in the weld pool is kept from leaking into the main force of surface tension. It is therefore necessary to reduce its size, for which the electrode tip from time to time assign to the side of the bath, allowing it to partially crystallize. The width of the rollers and decrease shayut to two or three diameters of the electrodes. Apply reduced by 10-20% and a current electrode of smaller diameter (vertical and horizontal joints not more than 5 mm for ceiling not exceeding 4 mm).
Welding of vertical joints can be performed on the rise or descent. When welding on the rise of the underlying crystallized weld metal helps to keep the molten metal weld pool. In this method facilitates the penetration of the root joint and edges, as the molten metal flows' with them in the weld pool, improving the conditions of heat transfer from the arc to the base metal. However, the appearance of the seam - grubocheshuychaty. When welding the trigger to get a quality hard penetration: slag and molten metal seep under the arc and from further draining held only by the pressure of the arc and the surface tension. In some cases, they are insufficient, and the molten metal is derived from the weld pool.
Horizontal welding of butt joints is more difficult than vertical, due to the draining of the molten metal from the weld pool at the bottom edge. As a result, may be formed on the upper edge of the undercut. When welding metal increased thickness usually make only one bevel the top edge, bottom helps to keep the molten metal in the weld pool. Welding horizontal fillet welds in lap joints does not cause problems and techniques does not differ from welding in the down position.
Welding of joints in the overhead position is more difficult and should be avoided whenever possible. Welding is performed by periodic short-circuit the end of the electrode to the weld pool, during which the metal weld pool is partially crystallized, which reduces the volume of the weld pool. At the same time, the molten metal electrode is introduced into the molten bath. When extending the arc formed undercuts. When welding these joints worsened conditions for the allocation of the weld pool of molten metal slag and gases. Therefore, the properties of the weld metal is somewhat lower than when welding in other spatial locations.
Welding technique and slash cork compounds does not differ from the techniques discussed above or butt welding of fillet welds.
Depending on the length of the seam thickness and grade of metal, rigidity, etc., using various methods of welding seams, and the sequence of filling the cuts. Naprohod welding is usually used for welding of short seams (up to 500 mm). Welds up to 1000 mm is better to weld from the middle to the ends or the step-back method. At last all the way to the seam is divided into sections of 150-200 mm, which should be a multiple of the length of the plot, one electrode is deposited. Weld seams in critical structures of thick blocks of performing, stage or slide, which allows to influence the structure of the weld metal and welded joint and its mechanical properties.
See also:
Manual Arc Welding
Introduction to Arc Welding
Creating and maintaining an arc
Ways to improve performance
Technique of upper and horizontal joints
Technique of the lower seam
Pipe Welding Technique
The Method
Arc Welding in Protective Gases
Electrodes for Manual Arc Welding
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