It has good but restricted weldability due to its high strength.
Key points about weldability
Carbon equivalent is higher
Q460NH uses more manganese, niobium, vanadium for high strength, so its cold-crack sensitivity is higher than Q355NH.
Preheat is often required
Thickness ≤ 16 mm, ambient > 5°C: usually no preheat
Thickness > 16 mm or low temperature: preheat to 80–150°C
Thick plates over 30 mm: must preheat to avoid cracking
Welding processes are all applicable
SMAW, MIG/MAG, FCAW, SAW all work normally, as long as heat input is controlled.
Filler metal recommendation
Use high-strength weathering matching electrodes/wires
E8018‑W, E9018‑W
ER80S‑W, ER90S‑WFor unpainted outdoor use, matching filler ensures consistent corrosion resistance.
Heat input control
Avoid excessive heat → HAZ softening and strength loss
Avoid too-low heat → high hardness and cold crackingModerate, stable parameters work best.
Interpass temperature
Keep ≤ 250°C to prevent grain coarsening and toughness drop.
Post-weld treatment
Stress relief annealing is not required for general structures
Only needed for extremely heavy, highly restrained components
