课题研究了海洋工程用厚钢板夹杂物诱导晶内针状铁素体形核机理，建立了夹杂物对微观组织的定量调控机制并建立强韧化模型；开发出了 EH420~EH550 系列海洋工程用大线能量焊接厚钢板，力学性能满足标准规范要求，分别实现了 50~200kJ/cm 以上大线能量焊接，具备优异的低温韧性；开发出了大线能量焊接海工钢配套焊材，实现焊缝性能与母材良好匹配。本课题数据集以宝钢、河钢、大西洋焊材、东北大学和哈尔滨工业大学研究过程数据为主，数据量约150M，共享方式为协议共享，延期2年。

The subject studied the nucleation mechanism intragranular acicular ferrite induced by inclusions in thick steel plates for offshore engineering, and clarified the rule for quantitative controlling microstructure by inclusions and the effect on strength and toughness. EH420 to EH550 grade steel plates have been developed with high-heat input weldability of 50-200 kJ/cm and qualified mechanical properties. They also exhibited excellent low-temperature toughness. Welding consumables suitable for high-heat input welding steel plates for offshore engineering have also been developed .The sub-dataset were from Baosteel, HSC, Atlantic welding materials, Northeastern University and Harbin Institute of Technology research-based process with a data size of 150M, which will be publicly shared under the agreement in 2 years.