Welding method of railway passenger vehicle weather-proof steel sleeper beam complex cross structure

Abstract

The invention discloses a welding method of a railway passenger vehicle weather-proof steel sleeper beam complex cross structure. The welding method of the railway passenger vehicle weather-proof steel sleeper beam complex cross structure includes the step of welding the weather-proof steel sleeper beam complex cross structure by adopting a dual-step lift, fall and return method which includes: step 1, performing lift welding on the position of a right weld toe of a weld joint I, marking the lift welding length as L, falling to the position half of the length L in fall welding, and then completing the first step by performing return welding to an intersection of the first-step lift welding right weld toe and the position of an upper weld toe of a weld joint II; and step 2, performing liftwelding on the position of a left weld toe of the weld joint I, then performing return welding to the position of a lower weld toe of the weld joint II after falling by one half in the second-step fall welding, completing the second-step lift, fall and return welding, and finally performing continuous weld so as to complete the whole operation. The welding method of the railway passenger vehicle weather-proof steel sleeper beam complex cross structure improves fusion performance of an intersection joint, not only can realize the purpose of improving post-welding one-time flaw detection passingrate to 70%, but also obtains the weld joints easy to polish after the welding, enables flaw detection rate to reach 100% after polishing, avoids a reworking procedure, reduces production cost, and improves production efficiency, and above all, the quality of the joint is effectively guaranteed.

Description

technical field [0001] The invention belongs to the technical field of welding, and relates to a welding method for a complex cross structure of a weather-resistant steel bolster beam of a rail passenger car. Background technique [0002] With the rapid development of my country's rail transit, how to control the production quality under the premise of ensuring production efficiency has become the most important issue. At present, there is a serious production bottleneck in the manufacture of the chassis at the end of the car body, that is, there are many complex intersection structures inside the car body bolster, such as figure 1 As shown, the pass rate of the post-weld appearance inspection and surface penetration inspection is low, and there are multiple repairs, which seriously affect the production progress and increase the production cost. Therefore, based on this technical background, this patent proposes a solution to the problem of difficult flaw detection of comp...

AI Technical Summary

Problems solved by technology

[0003] At present, there are two most suitable welding methods, but the effect is not significant, and the production cost cannot be reduced and the production efficiency can be improved.

[0004] The first such as figure 2 The three-point intersection method shown in the figure has the advantage of being relatively simple to operate, and the three welds meet at one vertex; but the disadvantages are also more obvious, such as unfused, arc crater cracks, arc crater shrinkage and other defects are very easy to appear at the intersection, and Due to the special position of the intersection point, it is impossible to eliminate the defects by grinding. TIG (argon arc welding) remelting is required, which requires many repairs and long working hours. Taking 16 working hours of a car for a corbel beam as an example, there are 40 such structures in this process. , the average number of defects in a single corbel is about 80, the average time for flaw detection and repair is 10 hours, and it takes 160 hours for a car, and the single welding time for this process is only 4 hours

The overall production schedule of a single corbel (including overall assembly, welding, grinding, and repair) is required to be 10 hours, and the overall production schedule of a vehicle corbel is 160 hours. The time for flaw detection and repair seriously affects the progress of subsequent processes.

[0005] The second is as image 3 The two-point intersection method at the apex is shown. Based on the first improvement scheme, the continuation welding is introduced, and the original three welding seam intersection is improved to the second welding seam for continuation welding, so as to avoid the arc-stop joint staying at the apex. However, although this method avoids arc crater cracks and arc crater shrinkage defects at the vertex, there are still unfused defects at the vertex. After judgment and analysis, it is difficult for the operator to observe the shape of the molten pool at the corner position during continuous welding. There is a blind judgment in the fusion with the base metal, which is likely to cause no fusion

Also, TIG (argon arc welding) remelting is required to eliminate defects at the apex. Taking 16 corbels in a car as an example, the average number of defects in a single corbel in this process is reduced to 40, and the average time for flaw detection and repair is 7. Hours, a car needs 112 hours, and the single welding time of this structure is also 4 hours, so although the flaw detection and repair time is reduced, it still seriously restricts the production schedule

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