With relatively poor weldability, 1045 steel is not suitable for direct welding.
The core issue of 1045 steel in welding is its high hardening tendency, which causes martensite formation in the heat-affected zone and increases the risk of cold cracking.
How to prevent？Key points:
- Preheating is required (150–300℃).
- Use a low-hydrogen welding process.
- Control welding heat input; interpass temperature should not exceed the preheating temperature.
- Post-weld slow cooling + stress-relief annealing