1. Control of welding line energy
Welding should be carried out strictly in accordance with the LR AH32 shipbuilding steel plate process specification, and the welding heat input is generally controlled below 5000J/cm. If the heat input is too large, the weld metal will stay in the LR AH32 shipbuilding steel plate at high temperature for a long time, which will cause the heat-affected zone to overheat and coarsen the crystal grains, make the structure plasticity worse, and reduce the crack resistance of the joint.
If the heat input is too small, the cooling rate of the joint will be accelerated, the cooling time will be shortened, and the heat affected zone of the LR AH32 shipbuilding steel plate will be hardened, which is not conducive to the escape of hydrogen, so it also increases the cold cracking tendency of the LR AH32 shipbuilding steel plate. Therefore, the welding heat input should be strictly controlled during construction.
2. Operational control
The welding environment of LR AH32 shipbuilding steel plate should be stable to avoid air flow affecting the gas protection effect. Try to avoid welding the LR AH32 shipbuilding steel plate in a humid environment. Due to the multi-pass welding, the splash cleaning between layers must be thorough. Before welding on the back, use gouging to thoroughly clean the roots, grind the grooves, and clean them before welding.
