Research on the technical problems after the trans

Research on technical problems of steel barrel seam welding machine after transformation (Part 2)

3. Welding time and rest time

during barrel body seam welding, the nugget size is mainly controlled by welding time, and the overlap is controlled by cooling time. At lower welding speed, the ratio of welding to rest time is 1.25:1~2:1, and satisfactory results can be obtained. When the welding speed increases, the spacing of welding points increases. At this time, in order to obtain welds with the same overlap, this proportion must be increased. Therefore, at higher welding speed, the ratio of welding to rest time should be 3:1 or higher

4. Welding speed

the welding speed of the barrel body is directly related to the thickness and material of the barrel body material. The welding parameters of special steel barrel plates produced by different manufacturers are also different during welding. Here we will not list them one by one. In a word, the welding speed determines the contact area between the welding roller (welding wheel) of the barrel body seam welder and the barrel body, and the contact time between the welding wheel and the heating part (weld lap). When the welding speed increases, the welding current must be increased in order to obtain sufficient heat. Excessive welding speed will cause burning of barrel body surface and electrode adhesion. Therefore, even if the current barrel body seam welding machine has sufficient external cooling water, the welding speed should not be too large, but should be limited

II. Influence of the mechanical part of the welder and the previous process of the barrel body on the welding quality of the barrel body. Generally, electrode pressure and welding speed are parameters that do not change frequently when welding the barrel body. Unless the material thickness of the barrel body changes greatly, this parameter will change accordingly. When the material thickness of the welded barrel body is 1.2 or 1.0, the electrode pressure and welding speed may not change, and the welding quality of the barrel body will not be affected. However, if the barrel support is too high or too low, the electrode pressure during barrel welding will be directly changed. If the barrel support is too high, the electrode pressure will increase, and the welded barrel will have obvious indentation. As we mentioned earlier, R decreases significantly with the increase of electrode pressure. At this time, the welding heat generated by welding will decrease with the decrease of electrode resistance R, and the welding strength will also decrease with the increase of electrode pressure. Therefore, leakage or flange cracking; If the barrel holder is too low, the electrode pressure will decrease, and the welded barrel body will produce an obvious peach shape, that is, the outside of the barrel body weld is too high, not an arc. When the electrode pressure decreases, R increases obviously. At this time, the welding heat generated by welding will increase due to the increase of electrode resistance R, resulting in burn through or splash, and leakage or flanging fracture

after checking the height of the bracket of the complete barrel body seam welding machine, its levelness shall be adjusted, and the parallelism of the bracket shall be adjusted with a level instrument until it is horizontal. If the two ends are uneven, the order of the electrode press extruder enterprise will get a large rebound force, resulting in different welding strength at the end of the barrel body weld, so leakage or fracture will occur

secondly, check whether the sewing machine head is normal. Sometimes, the lower head swings or the upper head dries due to long-term poor lubrication, so that the upper head cannot be moved down to the position required by the process. These are the main factors affecting barrel body welding, which we have encountered in production

third, check whether the air pressure is correct and whether the air pipe and air valve have air leakage

fourth, check whether the lap size of the two ends of the barrel body spot welding is correct. If the process stipulates that the lap size of the barrel body is 4 mm, there should be no excessive error at both ends, otherwise one end of the barrel body will leak after welding

III. The simplest way to solve the problem

previously, we theoretically analyzed the reasons for the leakage of the steel barrel body after welding, but generally, except for the equipment reasons, most of them are human factors. Therefore, when solving the problem, first check the lap width of the barrel body. If the lap width of the barrel body is appropriate, the simplest way is to adjust the welding speed to the lowest and weld. For each barrel body welded, increase the welding current appropriately according to the welding current. Until the current does not produce spurs, the welded barrel body will not leak. At this time, if you want to increase the welding speed, you should increase the welding current accordingly. The two complement each other. However, in order to speed up the work, many operators blindly increased the welding speed, resulting in the imbalance of the welding specification of the control box, resulting in leakage or cracking of the barrel body after welding. The following table is a group of process parameters in the production of a barrel making enterprise, which is only for reference. The welding parameters of the barrel body will be affected by the accuracy of the welding machine, the transformation mode, the accuracy of the controller, the working environment, the raw materials used, the proficiency of the operators and other factors

welding process parameter table of steel barrel

static tension and compression, static change, high-frequency tension and compression fatigue Low normal align=center> material thickness (mm)

normal align=center> welding voltage (V)

normal align=center> compressed air pressure (MPA)

normal align=center> welding power selects about 30 provincial-level new material R & D and utilization demonstration projects (KA) that are leading in the domestic industry

normal align=center> welding speed

normal> front section

normal> middle section

normal> rear section

normal align=center>1.0