Welding and Processing Techniques for ABS Grade EH32 Shipbuilding Steel Plates

1. Selection of welding consumables

ABS EH32 shipbuilding steel plates possess good inherent weldability due to their low carbon content. The welding consumables selected must comply with ABS certification standards:

Manual arc welding: Low-hydrogen carbon-manganese electrodes are recommended.

Submerged arc welding: Use solid welding wire with matching strength.

Note: Avoid using high-carbon welding consumables to prevent brittleness in the welded joint.

2. Welding Procedures

Preheating temperature: For plate thicknesses ≥20 mm, preheat to 60°C–100°C to eliminate welding stresses.

Welding current: 180–260 A (adjust according to wire diameter).

Interpass temperature: Maintain below 150°C to prevent grain coarsening.

Post-welding treatment: Cool slowly to avoid cracking caused by thermal stress.

3. Cutting and Bending

Cutting methods: Oxy-fuel or plasma cutting may be used.

Post-cutting treatment: Remove the oxide layer from the cut edges to prevent welding defects.

Bending:

Thin plates (<16 mm): Cold bending is permitted.

Thick plates: Hot bending is required to prevent surface cracking.

Bending angle: Must comply with ABS marine steel fabrication specifications to avoid excessive deformation.

4. Post-welding inspection

Upon completion of welding, the welded joints shall undergo:

Non-destructive testing: Ultrasonic testing (UT) and radiographic testing (RT) to identify defects such as porosity, cracks and inclusions.

Low-Temperature Impact Test: To be carried out on critical welded areas to ensure the toughness of the joint is not lower than that of the base material, thereby meeting marine structural safety standards.

5. Common Welding Defects and Remedies