Welding Properties and Key Process Considerations for ABS Grade E Shipbuilding Steel Plates

ABS Grade E is a low-carbon, low-alloy fine-grained steel with good weldability, but it is relatively sensitive to low-temperature toughness. To mitigate the risk of cold cracking and embrittlement, welding procedures must be strictly controlled.

I. Weldability Advantages

1. Low carbon equivalent (Ceq ≤ 0.40%): Reduces susceptibility to cold cracking.

2. Fine-grained microstructure: Ensures good toughness matching between the weld and the heat-affected zone (HAZ).

3. Low sulphur and phosphorus content: Reduces the incidence of hot cracking and inclusion defects during welding.

II. Key Process Requirements

1. Welding consumables

Use E70 series low-hydrogen electrodes or compatible submerged arc welding wires to ensure the weld’s impact toughness at -40°C is ≥27 J.

2. Preheating temperature

Thickness ≤25 mm: Room temperature to 50°C

25–50 mm: 80–120°C

≥50 mm: 120–150°C (to prevent cold cracks)

3. Interpass Temperature

Control at ≤200°C to prevent grain coarsening in the HAZ.

4. Post-weld Treatment

For thick plates or high-stress joints, hydrogen removal treatment at 200–250°C is recommended to reduce the risk of delayed cracking.

III. Preventive Measures for Common Defects