High frequency welded pipe equipment factory teaches you to judge the advantages and disadvantages of stainless steel pipe
Author： Source：TENYES ELECTROTHERMAL EQUIPMENT CO.,LTD. Date：2020-09-29
Welded pipe equipment, high frequency welded pipe equipment and brazing heater Baoding Tianyixing Electric Heating Equipment Co., Ltd. is a business entity integrating R&D, production, technology and service, specializing in the production of induction heating equipment such as high frequency, super audio frequency and medium frequency.
Tong long lap welding
Lap welding refers to the dislocation bonding formed after two edges of pipe blank are overlapped together. In terms of length, lap welding can be divided into long and short, and the length of lap welding is generally several meters or even longer. There are slight dislocations of a few tenths of millimeters and complete dislocations equal to the wall thickness. The main reasons for the long lap welding are as follows:
1 axial movement of extrusion roller
Because of the unstable positioning of the extrusion roller and the extrusion roller shaft, and the gap caused by the tight fit of other parts in the assembly, the extrusion roller will appear axial movement and radial swing, at this time, the hole pattern of the extrusion roller will not coincide, resulting in lap welding.
2 bearing damage
After the bearing is damaged, the normal position of the extrusion roller will be destroyed. Taking the two-roll extrusion roller device as an example, two sets of upper and lower bearings are usually installed in the extrusion roller. When one of them is damaged, the extrusion roller loses control, and the weld will be higher and cause lap welding. In the production operation, we can observe the swing of the extrusion roller. When the upper bearing is damaged, the swing range of the roller is larger, and when the lower bearing is damaged, the swing range of the roller is smaller, which is also related to the degree of bearing damage. After the bearing of the guide roller is damaged, it can not only control the weld direction of the pipe blank well, but also the guide ring may cause pressure loss to the edge of the pipe blank after the bearing is damaged, so that the weld height changes, and a lap welding accident will occur if it is slightly inappropriate.
3 Bending of extrusion roller shaft
Taking the two-roll extrusion roll device as an example, there are two reasons for the bending of the extrusion roll shaft: one is the external bending due to the insufficient pressure of the top thread for a long time; One is the inner bending when the pressure of the upper jacking wire is too high. When checking, release the jacking device, and place the elevation of the steel plate ruler on the end face of the roller to check the inclination angle between the end face of another roller and the steel plate ruler. When the important official bends outside, the scratch is caused by the roller bending the shaft; When the important official is bent, scratches are caused by rollers that do not bend the shaft.
4. Large extrusion force
Overlapping welded pipes caused by excessive extrusion force generally occur in the production of thin-walled pipes, but rarely occur in the production of ordinary thick-walled pipes. This is because in the production of thin-walled tubes, due to the poor rigidity of the tube blank, once the extrusion force is too large, the width of the tube blank cannot be accepted after too much allowance is produced in the pass, and it will move to other spaces to form lap welding. Therefore, in pass design, it is necessary to select appropriate pass radius and roll gap allowance according to different tube wall thickness, and pay attention to moderate adjustment of extrusion amount.
5 Inclined guide roller
Under normal circumstances, the guide roller should be in a horizontal position. In order to better control the welding seam, the guide roller can be tilted. If the inclination angle is too large, the extension of the guide ring is too large. With the rotation of the guide roller, the roller ring will press the edge of the tube blank to deform abnormally, especially in the production of thin-walled tubes, it is easier to promote the production of lap welded pipes. Often, the large inclination adjustment of the guide roller is due to the fact that it can't control the pipe seam direction well. Therefore, when the pass of the guide roller is worn out, it is necessary to replace the new roller in time, and check and adjust it immediately when the center is not correct, so as to avoid large inclination adjustment as much as possible.
6 The bottom diameters of the upper guide rollers are different
If the bottom diameters of the two passes of the guide upper roller are not the same, the problem of overlapping welded pipes will easily occur, especially in the production of thin-walled pipes. When stopping the machine for inspection, you can feel whether the welding seam in the V-shaped area is flat or not by touching with your fingers. Of course, as long as we strictly control the quality of the rollers, this lap welding phenomenon can be overcome.
Baoding Tianyixing Electric Heating Equipment Co., Ltd. specializes in designing and manufacturing various types of high-frequency welded pipe sets, stainless steel precision welded pipe sets and high-precision steel-plastic and stainless steel composite welded pipe sets; Design and manufacture various types of welded pipe dies-rolls and special-shaped rolls, thus making the products serialized. The company has perfect scientific research and development and process design capabilities, rigorous and thorough quality assurance system, customer training system and pre-sale, in-sale and after-sale service system. It enjoys a high reputation among customers at home and abroad.
Baoding Tianyixing Electric Heating Equipment Co., Ltd. Address: No.129 Tengfei Road, Baoding Private Science and Technology Park, Hebei Province
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