U-Shape Hot Rolled Steel Sheet Pile Type 2 U9

1. Smelting & Continuous Casting

Process: Blast furnace molten iron is refined in a converter (BOF), with strict control over the chemical composition of carbon (C), manganese (Mn), and silicon (Si), and trace alloying elements (such as vanadium and titanium) are added to improve strength and toughness.

Output: The product is cast into shaped billets (dog-bone beam blanks) or large rectangular billets using a continuous casting machine (CCM). Using shaped billets significantly reduces deformation during subsequent rolling and protects the locking mechanism.

2. Reheating of Steel Billets

Process: Steel billets are uniformly heated in a walking beam furnace, typically at a temperature between 1150°C and 1250°C.

Purpose: To eliminate internal stress in the steel billet, achieving sufficient plasticity to facilitate subsequent high-temperature austenitic rolling.

3. Universal Rolling

This is the most crucial and technically challenging stage in sheet pile production:

Roughing: Heated steel billets are rolled through a roughing mill to initially shape the web and flange profiles of the sheet pile.

Universal Finishing: Multi-pass fine-tuning rolling is performed using a universal mill and an edge mill.

Interlock Forming: In the final few passes, specially designed lateral forming rolls precisely roll the interlocks at both ends of the sheet pile into U-shaped or Z-shaped interlocks. The dimensional tolerances of the interlocks are extremely high to ensure smooth driving and tight engagement during construction.

4. Cooling & Straightening

Cooling: The rolled red-hot steel sheet piles undergo step-by-step uniform cooling on a cooling bed to prevent warping due to temperature differences.

Straightening: After cooling, the sheet piles are straightened longitudinally using a large multi-roller straightener to eliminate bending and twisting, ensuring the straightness of the sheet piles meets standards (such as EN 10248 or JIS A5523).

5. Cutting, Inspection & Packing

Cutting: Using hot or cold saws, the sheets are precisely cut to the customer's required lengths (such as 9 meters, 12 meters, 15 meters, etc.).

Inspection: * Dimensional and Surface Inspection: Strict manual and automated inspections are conducted, especially the pass-through test, to ensure perfect splicing of each pile.

Physical and Chemical Performance Testing: Samples are tested for yield strength, tensile strength, and impact energy.

Packaging: Rust-preventive oil or waterproof sealant is usually applied to the interlocking areas, then the piles are stacked and bundled in alternating directions, ready for shipment.

Additional Notes: The above describes the process for hot-rolled sheet piles. Cold-formed sheet piles are made by bending hot-rolled steel coils at room temperature using a roll forming machine. Comparatively, the hot-rolling process offers superior interlocking tightness, watertightness, and overall structural strength, making it more suitable for large or deep foundation pit projects.