ATTEN: Manager Liu
ADD: Longhua Development Zone, Jing County, Hengshui City, Hebei Province
3.2 Parts lofting, blanking and cutting) The welding shrinkage allowance, press head allowance and cutting width allowance should be added according to the design drawings and process requirements. 2) Factory lofting, blanking and assembly ruler should be checked with acceptance ruler. 3) Material materials and specifications should be carefully checked before parts are laid out, so as to make special materials. No substitution is allowed at will, only substitution is needed. After cutting and blanking of the same 4 parts as the original design, the part number should be marked (stamped) at the obvious part of each part. 5) After cutting, the shape dimension must be re-measured, and the dimension must meet the accuracy requirement, otherwise the joint dislocation will be affected, and the center line and processing line 5 single-section tube lofting and shaking-out drawing (Shenzhen Airport large-diameter thick-walled conical pipe column manufacturing technology) 3,3 conical pipe rolling process) will be popped out to eliminate the remaining straight edges at both ends. A special die was developed to press the two ends of the part. The length of the die is 1/2L+ (30-50) mm (L is the center distance of the lower roll). Considering the rebound of the material, the curvature radius of the die is about 2% smaller than that of the cone tube radius R.
After pressing head at both ends of the part, special testing sample is used for testing. The chord length B of the sample is 0.5D (and not less than 500 mm), and the gap between the sample and tile should be less than 15 mm. After the indenter is qualified, both ends are cut and the groove is opened at the same time. 3) Rolling with fast feeding method and multiple feeding method until the required requirements are met. Due to the rebound of steel plate, certain overwinding amount must be applied during rolling. In the rolling process, the radius at both ends of the child's bending plate should be continuously inspected by the template. Figure 6 is an example of cone tube rolling (Shenzhen Airport Large Diameter Thick Wall Cone Column Manufacturing Technology 4) in numerical control rolling. Repeated rolling on the plate machine, while paying attention to deformation control, until forming, after forming by special inspection of processing accuracy, otherwise the welding process of rolling correction 3.4 tapered pipe longitudinal seam is welded by semi-automatic arc welding, longitudinal seam splicing and positioning welding should be carried out before welding, the length of positioning weld should be more than 40 m, and the spacing of positioning weld should be 500-6. The thickness of positioning weld should not exceed 2/3 of the designed weld.
When welding, attention should be paid to the variable of edge misalignment and the gap between welds. 2) Before welding, the welding seam must be preheated in the range of 100mm on both sides. The ceramic electric heating plate is used to preheat the welding seam. The preheating temperature is 10050 degrees C. When heating, the heating temperature should be measured and controlled by thermometer and temperature controller at any time. 3) Weld the inner side first, and then weld the outer side. After filling the inner groove with 2/3 groove depth, the outer carbon air gouging is carried out to clear the roots, and the outer groove is welded, then the inner groove is welded to make the weld shape. Nondestructive testing of weld seam was carried out after complete cooling. 3.5 Welding technology of longitudinal seam of tapered pipe 1) Before long butt joint, single tapered pipe joint must be corrected, especially the degree of trench must meet the requirements of specifications. 2) When assembling adjacent pipes, the longitudinal seams should be staggered by 120 degrees, and the ellipticity, verticality and straightness of two ports must be guaranteed to meet the requirements of positioning welding. The positioning welding requirements are the same as those of the previous figure 7. After joining the whole pipe body, the upsetting sketch of the longitudinal seam of the cone pipe segment (Shenzhen Airport Large Diameter Thick Wall Cone Pipe Column Manufacturing Technology)3. The concentricity of the whole pipe body is measured by level or total station.
If the center points of the upper and lower end faces are in a straight line, it means that the concentricity of the pipe body meets the requirements. Otherwise, it shall be spliced and corrected again until the concentricity meets the requirements.