Commonly Used Welding Materials?
Manual Welding: E5015 (J507), E5016 (J506)
Submerged Arc Welding: H08MnA + HJ431
Gas Shielded Welding: ER50-6
Welding Preheating Temperature?
Plate thickness ≤25mm: No preheating
25–50mm: 80–120℃
50mm or Q345E: 120–150℃
Is Post-Welding Heat Treatment Required?
General Structures: No
Thick Plates (>50mm), Pressure Vessels, or High-Stress Components: Stress-Relief Annealing (600–650℃)
Will Cold Working Cause Cracking?
With proper processes, it will not. Q345 has good cold bending performance (no cracks at 180°), but for thick plates/low temperatures, the following is required:
Preheating (50–100℃)
Bending mandrel diameter ≥ 2 times plate thickness.
What precautions should be taken after flame cutting?
A 2-3mm hardened layer (martensite) will form at the cut edge, which is prone to cracking. Recommendation: