ASTM A36 WELDED BEAMS & COLUMNS

Introduce

ASTM A36 Welded Beams & Columns Production Process Flow

The manufacturing process of ASTM A36 welded beams and columns is a comprehensive procedure involving material preparation, assembly, welding, straightening, inspection, and other key stages. Below is a detailed introduction to the complete production process:

1. Raw Material Preparation

• Steel Plate Selection: ASTM A36 carbon structural steel plates are selected to meet mechanical property requirements (e.g., tensile strength ≥400 MPa, yield strength ≥250 MPa) and chemical composition standards (C ≤0.26%, Mn ≤0.80%).

• Cutting & Blanking: Flame cutting, plasma cutting, or laser cutting is used to shape the steel plates into flanges and webs. The cut edges are then cleaned to remove burrs and oxide layers.

2. Edge Beveling

• V-groove or U-groove bevels are machined on the edges of flanges and webs to ensure proper weld penetration. This is typically done using milling or planing machines.

3. Assembly & Alignment

• H-beam Assembly: An assembly machine aligns the web and flanges into an I-section, secured with clamps. Strict control is maintained over web eccentricity and end-face perpendicularity.

• Tack Welding: Temporary spot welding fixes the components in place to prevent deformation during full welding.

4. Main Welding Process

• Submerged Arc Welding (SAW): A twin-wire SAW machine performs fillet welding on the T-joints between flanges and the web. Welding is done in two passes (one side first, then flipped for the other side), with parameters adjusted based on plate thickness.

• Gas Metal Arc Welding (GMAW): Used for thin plates or local repairs, typically with CO₂/MAG shielding gas.

• Preheating Control: If plate thickness exceeds specifications (e.g., ≥25 mm), preheating to 100–150°C is required to minimize cold cracking risks.

5. Post-Weld Treatment

• Weld Cleaning: Removal of slag, spatter, and visual inspection for defects (e.g., undercut, porosity).

• Stress Relief: If necessary, annealing (heating to 600–650°C followed by slow cooling) is applied to reduce residual welding stresses.

6. Straightening & Shaping

• Mechanical Straightening: Roller straighteners or hydraulic presses correct flange angular distortion or web buckling, ensuring straightness tolerance ≤L/1000 (max. 3 mm).

• Flame Straightening: Localized heating and water cooling adjust minor deformations.

7. End Machining

• Sawing or milling trims the beam/column ends to final length, ensuring end-face perpendicularity and flatness (tolerance ≤1 mm/m) for on-site installation.

8. Quality Inspection

• Non-Destructive Testing (NDT): Ultrasonic (UT) or radiographic (RT) testing is conducted on main welds per AWS D1.1 standards.

• Dimensional Inspection: Key dimensions (section height, width, web thickness) are verified using calipers or laser measuring tools.

• Mechanical Testing: Samples undergo tensile, bend, and impact tests to validate material and weld joint performance.

9. Surface Treatment & Coating

• Abrasive Blasting: Achieves Sa2.5 cleanliness to enhance coating adhesion.

• Anti-Corrosion Painting: Primer (e.g., zinc-rich epoxy) and topcoat are applied, with a dry film thickness ≥80 μm.

Steel construction project

Standard Certificate

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