The effects of Ca treatment on the particle, microstructure, and toughness of heat-affected zone (HAZ) of shipbuilding steel with Zr–Ti deoxidation after high-heat-input welding were investigated. The simulated welding at a high-heat-input welding of 200 kJ/cm was carried out using Gleeble-3800 welding simulation. Then, particle characteristics were characterized using an Aztec-Feature automatic particle analysis system. Additionally, an in-situ observation experiment was performed to study the relationships between particle and microstructure by high-temperature confocal laser scanning microscopy (HT-CLSM). The results indicated that the average HAZ toughness at −40 °C was increased from 183 to 290 J by adding 0.0026 wt.% Ca. Meanwhile, the formation of acicular ferrite ratio was increased from 49.34% to 60.28% due to the addition of Ca. The scanning electron microscopy results clearly showed that CaO–Al₂O₃–TiO_x–ZrO₂–MnS particles could act as effective nucleation sites for the formation of acicular ferrite, which has been verified by the observation of the particle–microstructure relationship under HT-CLSM. Furthermore, particle characterization results show that the cumulative frequency of particles with the size of 1–3 μm was 33.2% in HAZ of Zr–Ti shipbuilding steel but 66.2% in HAZ of Zr–Ti–Ca shipbuilding steel.

研究了Ca处理对Zr-Ti脱氧造船钢高线输入焊接后热影响区（HAZ）的颗粒、组织和韧性的影响。使用 Gleeble-3800 焊接模拟进行了 200 kJ/cm 高热输入焊接的模拟​​焊接。然后，使用 Aztec-Feature 自动粒子分析系统表征粒子特性。此外，通过高温共聚焦激光扫描显微镜（HT-CLSM）进行了原位观察实验，以研究颗粒与微观结构之间的关系。结果表明，通过添加 0.0026 wt.% Ca，-40 °C 下的平均 HAZ 韧性从 183 J 增加到 290 J。同时，由于Ca的添加，针状铁素体的形成率从49.34%提高到60.28%。₂ O ₃ -TiO _x -ZrO ₂ -MnS 颗粒可以作为针状铁素体形成的有效成核位点，这一点已通过在 HT-CLSM 下观察颗粒-微观结构关系得到验证。此外，颗粒表征结果表明，尺寸为 1-3 μm 的颗粒在 Zr-Ti 造船钢 HAZ 中的累积频率为 33.2%，而在 Zr-Ti-Ca 造船钢 HAZ 中为 66.2%。