Seven major steel production processes (too complete)-5

SBS Steel Structure H. assembly 1) Before assembly, the staff must be familiar with the component construction drawings and the relevant technical requirements, and in accordance with the requirements of the construction drawings to review the quality of parts to be assembled. 2) due to the size of raw materials is not enough, or technical requirements to be spliced parts, the general must be completed before the assembly of the splicing. 3) The following provisions must be followed when using tread mold assembly: (1) The selected site must be flat and have sufficient strength. (2) The layout of the assembly mold must be based on the characteristics of its steel structure to consider the pre-welding shrinkage and other processing allowance. (3) Assembled after the first component, the quality inspection department must conduct a comprehensive inspection, after passing the inspection before proceeding to continue assembly. (4) Components in the assembly process must be strictly in accordance with the provisions of the assemble process, when there are hidden welds, must first welding, and after passing the test can be covered. When there are complex assembly parts are not easy to weld, can also be used while welding side of the welding method to complete the assembly work. (5) In order to reduce the deformation and assembly sequence, can be taken into the first component, and then assembled into a component method. 4) The choice of steel structure assembly method must be based on the structural characteristics of the components and technical requirements, combined with the processing capacity of the factory, machinery and equipment, etc., can effectively control the quality of assembly, high production efficiency. 5) Typical structural assembly (1) Welding h steel construction technology Process flow Cutting → assembly → welding → correction → secondary cutting → making hole → welding other parts → calibration grinding (2) Box section structure of the processing technology (3) The strength of the cross column processing technology (4) General coil process flow chart 1) Preassembled number according to design requirements and technical documents. 2) The principle of selection of pre-assembled parts: as far as possible the selection of the main force frame, the node connection structure is complex, component tolerance close to the limit and representative of the composite components. 3) Pre-assembled in a solid, solid platform-type tire rack on its support point level: A ≤ 300 ~ 1000m2 tolerance ≤ 2mm A ≤ 1000 ~ 5000m2 tolerance <3mm Note: (1) all components in the pre-assembly should be controlled according to the size of construction drawings, the center line of the rod should be confluent to the center of the node, and completely in a free state, not allowed to force fixed. Single-member support points regardless of the column, beam, support, should not be less than two support points. (2) Pre-assembled components control the baseline, the centerline should be clearly marked and consistent with the platform baseline and ground baseline. The control datum should be consistent with the design requirements, and the design approval should be obtained if the pre-assembled reference position is to be changed. (3) All the components to be pre-assembled, the production must be completed by the inspector and meet the quality standards of the single component. The same single component, should be interchangeable, without affecting the overall geometry. (4) in the tire frame pre-spell the whole process, shall not use components such as flame or mechanical modification, cutting, or the use of heavy ballast, collision, hammering. (5) Large frame open pre-assembled inspection time, it is recommended before sunrise, sunset after the regular. The accuracy of the tape used should be consistent with the installation unit. 1) high-strength bolt connector pre-assembled, can be used to nail positioning and temporary bolts fastening. The bolts shall not be less than 30% of the bolt holes in a set of holes and not less than 2. The number of stakes should not exceed 1/3 of the temporary bolts. 2) After the pre-installed application of the test hole inspection, when the hole with a nominal diameter of 1.0mm smaller test hole inspection, the pass rate of each group of holes is not less than 85%; when the diameter of 0.3mm than the nominal diameter of 0.3mm Check the pass rate of 100%, the test hole must be free to wear freely. 3) Check the holes that cannot pass through this procedure 5) to allow repair holes (hinges, grinding, scraping holes). After the repair hole, such as super-standard, allowing the use of material with the base metal to match the welding of welding, re-hole, but not allowed in the pre-loaded frame.