Full penetration welding method for U ribs

Abstract

The invention provides a full penetration welding method for U ribs. According to the method, a reverse dip angle is arranged on a to-be-welded panel relative to the horizontal plane during backing welding, a poly-arc pulse deep penetration welding gun at a specific angle is matched to carry out welding, and through gravity, a phenomena of embossment and undercut caused by tensile force on the surface of molten iron can be overcome, so that full penetration welding between U ribs and panel welding seams is well completed, and the forming at the inner side and outer side is favorable. Through full penetration welding seams, net sectional areas of the welding seams are ensured, so that equal strength between the welding seams and base materials is ensured, the phenomenon of stress concentration of welding seam roots due to partial penetration is avoided and the anti-fatigue performance of welding joints is effectively enhanced.

Description

technical field [0001] The invention relates to a welding method, in particular to a U-rib full-penetration welding method. Background technique [0002] With the advantages of light weight and fast construction speed, orthotropic steel bridge decks have been widely used in large and medium-span steel bridge decks at home and abroad. Steel bridge deck structures such as figure 1 shown. Due to the narrow, long and closed structural characteristics of the U-rib itself, the traditional U-rib and the panel are welded with an outer single-side fillet weld, and the weld penetration is 80% of the thickness of the U-rib. During the use of the bridge, the steel bridge deck is subjected to alternating loads of vehicle wheel pressure, which will cause fatigue cracks at the inner root of the U rib, resulting in the location of the U rib weld becoming a high-risk area for steel bridge safety hazards. The quality of the weld between the U rib and the deck Good or bad, directly affects t...

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Problems solved by technology

However, the inventor found in further research that since the deep penetration welding in this patent document adopts flat welding, the back of the weld is easy to form a convex undercut phenomenon during the solidification process because of the surface tension of molten iron, such as figure 2 As shown, the uneven transition formed by the weld protrusions is likely to cause stress concentration. During the service process, due to the alternating load caused by the running of the vehicle, fatigue cracks tend to be serious, and ultimately reduce the service life of the bridge.

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