Steel structure processing quality control

Quality control of steel structure processing

The quality control of steel structure processing mainly lies in the whole process tracking inspection and control in the production process, mainly in the following points:

1. Detailing of steel structure drawings:

The detailed design drawings should improve the structure and joint structure of the steel structure according to the design drawings. Analyzing the deformation of welding and structural stress, and put forward the measures to deal with the pre-deformation of the structure.

Indicate the number, positioning ruler, weight, material and other information of the component in detail. It should be able to reflect the overall three-dimensional relationship of the project, the main control coordinates and other macro information, so as to facilitate the measurement and control during installation.

According to the lifting requirements of the site, it is divided into sections, and the installation deviation, welding seam shrinkage deformation and other factors are fully considered. Curtain wall embedded parts, operating platform.

2. Steel structure raw material control:

1. Steel: The quality certificate or The inspection report, chemical composition, mechanical properties and other quality requirements must comply with the current national standards.

According to the steel quality certificate and the size specification table, check and check one by one, and check the surface quality, thickness, and local flatness of the steel. Defects such as delamination and slag inclusion.

2. Welding materials: The welding materials used must match the steel used in this project. Due to the different quality of different production batches, they should be divided according to the requirements. Batch check.

Welding rods and fluxes should be kept properly and should not be affected by moisture, otherwise it will not only affect the process performance of the operation, but also adversely affect the physical and chemical properties of the joint. If the welding material is placed for too long or gets wet, the welding test should be re-executed.

3. Control of blanking and hole making of steel structure:

Cleanliness of steel surface before cutting, Flatness, cutting size, section roughness, verticality, notch depth and bevel angle meet the requirements; the surface of assembly and welding places need to be treated.

Steel structure processing hole making

Lofting: the assembly of each component and part, the assembly of pre-assembled components requires professional lofting workers on the processing surface and assembly large sample board to accurately Stake out. After setting out, it must be inspected by the inspector to ensure that the geometric dimensions and angles of the components are accurate.

The drilling template, the connecting plate after drilling, the gusset plate corresponds to the reference line on the body; the eccentricity of the hole, the offset of the hole distance, the hole distance, the roundness The surface quality of verticality, hole wall and hole edge should be strictly controlled. In order to ensure the accuracy and quality of drilling, when using die drilling, there must be a stakeout worker to draw out the reference axis and the center of the hole.

Fourth, the steel structure assembly control:

The strength, stiffness, level of the assembled working platform and the tire frame Degree and related fixtures; dimensions of large samples and special molds; material, number, size, machining accuracy, quantity, connection and surface treatment of welding parts of parts and components; datum plane, datum line, cross center line, parts and components assembly position line; assembly position, direction, angle, concentricity, verticality, camber, bevel angle, blunt edge, gap, backing plate closeness and joint dislocation; assembly sequence and method , the welding shrinkage and machining allowance of the additional placement; the size, length, spacing, position and surface quality of the tack welding.

Assembly of components: assembly of components refers to the spot welding positioning and fixing before submerged arc welding. Before assembly, the small materials should be corrected, and the center line and positioning line should be drawn by the lofting personnel. , After the inspection is passed, the spot welding is allowed to be fixed, and the formal welding should be delivered after the inspection.

Fifth, steel structure correction:

Correction: correction work runs through the whole process of steel structure production, from before cutting It is necessary to correct the blanking, submerged arc welding, assembly manual welding, etc. to ensure that the size, quality and shape of the components meet the requirements of the specification, and strictly control the bending and twisting deformation.

Friction surface treatment: The end of the connecting friction surface of the component should be milled flat by a milling machine, and the friction surface is treated by a shot blasting machine to produce rust under natural conditions. . At the same time, the same material and processing method should be used to make the test piece, and the friction coefficient test should be carried out to ensure that the friction coefficient meets the specified requirements.

Component surface treatment: The processed parts, components and components should be edge-processed according to regulations to remove burrs, welding slag, welding spatter, dirt, etc. Check. After the components are finished and the surface is cleaned, use a shot blasting machine for surface rust removal.

Six, steel structure finished product inspection

Drawing number, component number, axis line, zero line, 1m elevation Stamp marks such as lines and their orientation and location. The overall length, section size, curvature, twist, camber, inclination of both ends, the diagonal of the plane, the groove of the welding on site, the hole spacing of the installation holes, whether the position size is qualified, the appearance quality and cutting of the component Chamfering of free edges, etc.