Abstract: The use of automatic welding technology is a development direction of large spherical tank welding. At present, the gas shielded flux cored wire used is imported wire, which is expensive and has a long lead time. In addition, due to the limitation of the track function, it is difficult to cover all the weld bead of the ball can. Therefore, most of them use the process of automatic + electrode arc welding. In this paper, the domestic welding technology of flux-cored wire and imported automatic welding machine and domestic semi-automatic welding machine are studied. The welding method of domestic welding material and automatic welding and semi-automatic welding machine is adopted, which reduces the cost and improves the welding method. Work efficiency has reduced labor intensity and achieved good economic and social benefits. Through the comparison and analysis of the above data, the chemical composition and mechanical properties of the domestic gas shielded flux-cored wire are equivalent to the quality of the imported wire, and some indexes are better than the imported wire, which can fully meet the requirements of 16MnR welding performance. According to the provisions of GB12337-90 "Steel Ball Storage Tank" and JB4708-92 "Steel Pressure Vessel Welding Process Evaluation", the material and wall thickness of the billiard tank are determined, and the Y-groove butt crack test and docking stand Welding and transverse welding are two process evaluations. The welding equipment is (LINCOLN) DC-400 DC arc welding power source, LN-9 wire feeder, BUG-0 crawling mechanism and semi-flexible track. The test board is made of 16MnR and has a thickness of 48mm; it is reverse polarity. Pre-heating 80 °C, 100 °C, 120 °C oblique Y groove butt crack test results show that no cracks were found on the surface, root and section of the test piece weld, but according to the "steel ball type tank" preheating temperature Do not lower than 100 ° C, the minimum temperature is determined to be 120 ° C. The process evaluation test groove size plus Figure 1, preheating temperature 120 ° C -170 ° C, welding process parameters are shown in Table 3. After welding, according to JB4730-94 standard 100% X-ray film, a total of six shots are grade I. The tensile strength, cold bending and impact values ​​of the welded joints meet the requirements (see Table 4). The window-shaped restraint crack test was carried out in accordance with the provisions of Appendix B of GB12337-90 <Steel Ball Storage Tank>, and no crack was found as a result. Through the above series of test results, it is shown that the domestic welding wire can completely replace the imported welding wire for the welding of 16MnR spherical tank. The use of domestic gas-protected flux-cored wire in ball automatic welding greatly reduces the cost, and the use of semi-automatic welding instead of electrode arc can improve production efficiency and reduce labor intensity. Our company used the above welding process to carry out on-site automatic welding of two 1000m3 spherical tanks in Binzhou, Shandong Province. Among them, the positive seam, the butt joint of the upper side board and the upper board adopt semi-automatic welding, and the appearance quality of the weld is good. The pass rate is 94.7% satisfactory. (1) It is technically feasible to weld 16MnN large spherical tanks with domestic gas-protected flux-cored welding wire, which not only guarantees the quality but also reduces the cost. (2) Semi-automatic replacement of welding rod arc welding is used to complete the welding of the automatic welding in the spherical tank construction, which reduces the welder's labor intensity and improves the production efficiency. (3) It has certain social benefits and good economic benefits. TAISHAN CITY WANAN CABLE CO.,LTD , https://www.tswanan.com
Key words : spherical tank welding material, automatic welding
Foreword automatic welding technology of spherical tanks has been gradually valued and promoted in China, but most of them use imported welding machines and imported gas-protected flux-cored welding wires. The imported welding wire is expensive (about 35,000 yuan per ton), and the delivery period is long (about 2.5). -3 months) and other issues. In addition, since the track of automatic welding can only be horizontally bent and cannot be bent vertically, it is difficult to weld the joint between the plate and the side plate, and the automatic welding of the position of the seam can not effectively solve the problem of splashing and clogging the nozzle. Therefore, conventional electrode arc welding is still generally used. In view of the above problems, we use the domestic gas-shielded flux-cored wire and the domestic semi-automatic welder (Time ZP7-500) in combination with the imported automatic welder in the assembly welding degree of the spherical tank stadium, which not only guarantees the product quality and reduces the quality of the product. The cost and work efficiency have been improved, and the development of national industry has been promoted, and good economic and social benefits have been achieved.
First, the choice of welding materials
The choice can not only ensure product quality but also reduce cost. „„Welding materials are one of the key issues in the promotion and application of automatic welding technology for spherical tanks. At present, there are many manufacturers of gas-cured flux-cored welding wire in China. We choose E712C welding wire produced in Shanghai. The performance comparison and weldability test were carried out. The E712C welding wire is easy to start the arc, the slag is good, the surface of the weld is smooth, the arc is stable, and the mechanical properties are good. The domestic welding wire and the imported welding wire (E71T-1) The chemical composition and mechanical properties of the deposited metal are shown in Tables 1 and 2.
Second, the welding process test
Third, economic accounting
Fourth, the conclusion