Holding the gun perpendicular to the weld joint gives moderate penetration. Forehand welding using a push travel angle provides the least penetration. Switch to forehand welding on thin metal.įigure 9-43 shows that the penetration in forehand welding is less than the penetration in backhand welding. When welding on thin base metal, backhand welding can burn through the base metal. A run-off tab can also be used to eliminate the crater at the end of a weld.īackhand welding with a 5°–15° drag travel angle allows for good weld bead control and produces good penetration. No matter what type of weld is made, this same finish movement can be made. This movement helps reduce the crater that occurs if the weld is stopped at the end of the joint. See Figure 9-45.īacktrack over the completed weld for about 1/4″ (6mm) when the end of the joint is reached. With practice, gun angles and travel speed are mastered to produce a uniform width bead with uniform ripples in the weld face. Adjust the position of the gun to maintain a C-shaped weld pool. Point the electrode more toward the surface if the edge begins to melt too quickly. When the trigger on the gun is pulled, an arc forms, and a C-shaped weld pool is created. The electrode and gun should be tilted between 5°–15° forward from a true vertical position. To make the fillet weld, the centerline of the electrode should be held at about a 45° work angle. Tack welds hold the pieces in position while the weld is made. It should be tack welded about every 3″ (75mm). The metal should be set up as shown in Figure 9-44. Base metal positions and gun angles apply to both GMAW and FCAW. The method used depends on the metal thickness and other factors. Any of the metal transfer methods may be used in the flat welding position. The face of a weld made in the flat welding position should be horizontal or nearly horizontal.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |