Based on many years' experience and related data of domestic counterparts, this paper expounds the main types of steel structure deformation, and introduces the construction method of flame correction of welding deformation.
Keywords: flame correction welding deformation construction method
At present, steel structures have been widely used in factory buildings. The main components of steel structure workshop are welded H-beam columns, beams and supports. These parts have welding deformation problems in the manufacturing process. If the welding deformation is not corrected, it will not only affect the overall installation of the structure, but also reduce the safety and reliability of the project.
The deformation of welded steel structure exceeds the allowable deformation range of technical design and should be corrected to meet the product quality requirements. Practice has proved that most deformed members can be corrected. The method of correction is to try to create new deformation to offset the existing deformation.
The commonly used correction methods in the production process mainly include mechanical correction, flame correction and comprehensive correction. However, flame correction is a difficult task, and improper method control and temperature control will also cause new and greater deformation of components. Therefore, flame correction should have rich practical experience. In this paper, the types and correction methods of welding deformation of steel structure are roughly analyzed.
1 steel structure welding deformation types and flame correction Six Musketeers Vocational Education Park (the largest free vocational education teaching resource website)
The main components of steel structure are welded H-beam columns, beams and braces. Welding deformation often adopts the following three flame correction methods:
(1) linear heating method;
(2) point heating method;
(3) Triangle heating method. The following describes the construction methods to solve different parts.
The following is the heating temperature of flame correction (low carbon steel).
Low temperature correction 500 ~ 600 degrees cooling mode: water.
Moderate temperature correction 600 ~ 700 degrees cooling mode: air and water.
High temperature correction 700 ~ 800 degrees cooling mode: air.
Attention: The heating temperature should not be too high during flame straightening, which will cause the metal to become brittle and affect the impact toughness. 16Mn cannot be cooled by water during high temperature correction, including steel with large thickness or hardening tendency.
1. 1 Angular deformation of flange plate
Correct the deformation of H-beam columns, beams and supports. Longitudinal linear heating (the heating temperature is controlled below 650 degrees) is carried out on the flange (outside the alignment weld), and the heating range cannot exceed the control range of two welding legs, so water is not used for cooling. Attention should be paid to linear heating:
(1) should not be heated repeatedly in the same position;
(2) Do not water when heating. These two points are the general principles of flame correction.
1.2 Upper arch, lower deflection and bending of columns, beams and braces
First, on the flange plate, facing the longitudinal weld, linear heating from the middle to both ends can correct the bending deformation. In order to avoid bending and deformation, the two heating belts should be synchronized. Low temperature correction or medium temperature correction can be adopted. This method is beneficial to reduce welding internal stress, but it is difficult to master because it shrinks longitudinally and laterally at the same time.
Second, the flange plate is heated linearly and the web plate is heated triangularly. This method is effective for correcting the bending deformation of columns, beams and braces. The transverse linear heating width is generally 20-90 mm, and the heating width is narrow when the thickness of the plate is small, and the heating process should extend from the middle of the width to both sides. Linear heating is best carried out by two people at the same time. The width of the triangle heated separately should not exceed twice the thickness of the plate, and the bottom of the triangle is equal to the linear heating width of the corresponding wing plate. The heating triangle starts at the top, and then starts from .........
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