1. Raw Material Preparation: Laying the Foundation for Production
Raw Material Selection: Mainly low-carbon hot-rolled steel strips or billets, with Q235 being the most common grade, ensuring sufficient strength and plasticity.
Raw Material Pretreatment: Shears are used to cut the steel strips or billets into lengths suitable for rolling. Surface impurities such as rust and scale are also removed to prevent any degradation in subsequent forming.
2. Hot Rolling: The Core Forming Step
Heat Treatment: The pretreated raw material is fed into a continuous heating furnace and heated to temperatures between 1000°C and 1250°C. This high temperature softens the steel, facilitating subsequent rolling and forming.
Multi-Pass Rolling: The heated steel enters the rolling mill, where multiple sets of horizontal and vertical rolls work together to gradually roll the steel into an L-shaped angle iron cross-section.
Pre-rolling: The steel is first rolled into a rough, approximately angle iron shape, adjusting the overall dimensions. Finishing Rolling: Through subsequent, multiple passes of precise rolling, the angle iron’s side length, thickness, and right-angle accuracy are precisely controlled to ensure compliance with national standards.
3. Finishing Processing: Improving Finished Product Quality
Cooling: The rolled angle iron enters a cooling bed for natural cooling or accelerated cooling with water spray to prevent deformation at high temperatures.
Cutting to Length: The cooled angle iron passes through a flying shear and is cut into fixed lengths according to customer requirements or national standards (e.g., 6 meters, 9 meters, 12 meters).
Straightening: The cut angle iron is straightened by a straightener to correct any longitudinal curvature and cross-sectional angular deviations, ensuring the angle iron’s straightness and right-angle accuracy.
4. Surface Treatment and Inspection: Ensuring Product Compliance
Surface Treatment: Different surface treatments are applied depending on the application scenario.
Black Skin Angle Iron: No additional treatment is performed, retaining the original surface after rolling. This is cost-effective and suitable for applications without corrosion protection requirements. Galvanized Angle Iron: A galvanizing process creates a zinc layer on the angle iron’s surface, enhancing corrosion resistance and making it suitable for outdoor, humid environments.
Quality Inspection: Finished angle iron undergoes comprehensive testing, including dimensional accuracy (edge length, thickness, angle), mechanical properties (tensile strength, yield strength), and surface quality (absence of cracks, inclusions, and severe rust). Only qualified angle irons are allowed into storage or shipped.
Post time: Oct-17-2025