Welded Conveyor Chains

Welded Conveyor Chains

1. Core Definition & Product Overview

2. Key Structural Design & Welding Technology

2.1 Core Components & Welding Processes

• Link Plates: High-tensile carbon steel (Q345B) or alloy steel (42CrMo) cut via CNC flame/plasma cutting (tolerance ±0.5mm) for complex shapes, followed by shot blasting to remove surface oxides.

• Pins/Axles: Forged alloy steel pins (hardness HRC 45-50) that serve as the chain’s rotational axis; welded to link plates to eliminate pin loosening or disengagement under shock loads.

• Attachments: Custom welded cleats, flights, brackets, or crossbars (integrated with the main chain body) for material retention or workpiece positioning—no separate fasteners required.

• Welding Techniques:

1. MIG/TIG Welding: Used for critical load-bearing joints (e.g., pin-to-plate connections) to create dense, porosity-free welds with tensile strength ≥90% of base material.

2. Resistance Welding: Applied for high-volume production of standard chain links, ensuring uniform weld penetration and consistent joint strength.

3. Post-Weld Heat Treatment: Stress relief annealing (heated to 600-650℃ and cooled slowly) to eliminate welding residual stress and prevent crack formation.

2.2 Structural Advantages (vs. Assembled Conveyor Chains)

3. Core Performance Parameters

4. Typical Application Scenarios

4.1 Mining & Quarrying

• Bulk ore/conveyor systems (handles gravel, coal, and rock with high abrasion)

• Mine shaft hoisting chains (heavy-load vertical conveying)

• Crusher feed conveyors (shock loads from large rock fragments)

4.2 Construction & Waste Management

• Construction debris conveyors (handles concrete, steel, and demolition waste)

• Waste-to-energy plant conveyors (high-temperature, abrasive waste handling)

• Asphalt plant aggregate conveyors (hot aggregate up to 180℃)

4.3 Heavy Manufacturing

• Steel mill slab/billet conveyors (high-temperature, heavy-load metal handling)

• Foundry mold conveyors (shock loads from molten metal molds)

• Port/terminal bulk cargo conveyors (container/ore handling)

4.4 Agriculture & Forestry

• Log handling conveyors (large, irregularly shaped timber with high impact)

• Biomass fuel conveyors (wood chips, straw, and agricultural waste)

• Fertilizer production conveyors (corrosive bulk material handling)

5. Customization Options

• Attachment Designs: Welded cleats (angled 30°/45°/90°), flights (solid/perforated), crossbars, and grab hooks for material retention.

• Material Grades:

• Carbon steel (Q345B) for general heavy-duty applications;

• Alloy steel (42CrMo) for high-impact loads;

• Stainless steel (304/316) for corrosive environments (food/chemical industries).

• Surface Treatments:

• Hot-dip galvanizing (corrosion resistance for outdoor use);

• Tungsten carbide overlay (abrasion resistance for mining/quarrying);

• Heat-resistant paint (for high-temperature applications up to 350℃).

• Pitch & Width: Custom pitch (50-300mm) and chain width (100-1000mm) for wide conveyor beds.

6. Installation & Maintenance Guidelines

6.1 Installation Best Practices

1. Sprocket Matching: Use heavy-duty welded sprockets (tooth hardness HRC 45-50) with tooth profiles optimized for welded chain engagement.

2. Alignment: Ensure conveyor frames and sprocket shafts are aligned (misalignment ≤1mm/m) to avoid uneven wear on chain links.

3. Tension Adjustment: Maintain minimal slack (0.5-1% of chain length) to prevent chain sag under heavy loads; use take-up units for tension control.

4. Fastening: Secure chain ends to conveyor frames with welded brackets (not bolted connections) to handle shock loads.

6.2 Maintenance Protocols

1. Inspection:

• Check weld joints for cracks (use magnetic particle testing) every 1,000 operating hours;

• Inspect surface wear (replace chain if link plate thickness reduces by ≥10%);

• Verify attachment integrity (re-weld loose/broken attachments immediately).

2. Lubrication: No lubrication required for welded joints; apply anti-rust oil to exposed steel surfaces every 6 months (for outdoor use).

3. Replacement: Replace entire chain sections if ≥10% of weld joints show cracks or wear exceeds limits (do not repair individual links for safety).

7. Quality Assurance & Compliance

• Manufacturing Standards: Compliant with ISO 1977 (Conveyor Chains, Attachment Conveyor Chains and Associated Sprockets) and GB/T 8350 (Chinese National Standard for Welded Conveyor Chains).

• Testing Protocols: Every batch undergoes:

1. Tensile strength testing (universal testing machine) to verify load capacity;

2. Weld quality inspection (ultrasonic testing for internal defects);

3. Impact testing (Charpy V-notch test) to validate shock resistance;

4. Dimensional inspection (CNC measuring equipment).

• Certifications: CE (for EU market), ISO 9001 (quality management), and SGS certification for material compliance.