Q345级钛氧化物冶金钢生产工艺及大线能量焊接性能研究

Study on Production Technology and High Heat Input Welding Property of Q345 Grade Ti-oxide Metallurgy Steel

研究了工业化条件下钛氧化物冶金和TMCP工艺对Q345级钢板基体力学性能及大线能量焊接性能的影响。采用光学显微镜、扫描电镜、电子探针等手段分析了钢板显微组织及夹杂物特征,进行了大线能量焊接热模拟和气电立焊试验。结果表明,在钛氧化物冶金和TMCP工艺下,工业化试制钢板获得了良好的基体力学性能和大线能量焊接性能。钢中Ti、Mg、Ca等微细氧化物或氧硫化物均匀弥散分布,有效促进了焊接粗晶热影响区针状铁素体组织形成,200 kJ/cm线能量下焊接接头冲击韧性显著改善。

Effects of Ti-oxide metallurgy and TMCP process on the matrix mechanical properties and high heat input welding property of Q345 grade steel plate were studied under industrial conditions.Microstructures and inclusion characteristics were analyzed by OM,SEM and EPMA.High heat input welding simulation and EGW experiments were carried out.Results indicated that the industrially produced steel plates obtained good matrix mechanical properties and high heat input welding property.Fine-sized inclusions containing Ti,Ca and Mg were distributed uniformly in steel,which promoted the formation of acicular ferrite structure in CGHAZ effectively.Impact toughness of the weld joint under 200 kJ/cm was improved significantly.