Ti-Zr微合金化高强钢焊接热影响区性能及组织特征

研究了Ti-Zr微合金化高强钢100 kJ/cm大线能量焊接热模拟和192 kJ/cm大线能量电渣焊热影响区(HAZ)的力学性能和组织特征。研究表明:不同线能量下,HAZ均具有良好的强韧性;HAZ组织以针状铁素体为主,电渣焊HAZ组织相对粗大,并出现少量均匀分布的M-A岛;不同线能量下第二相夹杂物均为含Ti,Zr及Mn的复合氧化物,热模拟HAZ组织中夹杂物尺寸较小,且数量较多,对晶内针状铁素体形核促进作用更大。

Mechanical Properties and Microstructure Characteristics of Welding Heat Affected Zone of Ti-Zr Micro-alloyed High Strength Steel

The mechanical properties and microstructure characteristics of heat affected zones(HAZ) of 100 kJ/cm high heat input simulated welding and 192 kJ/cm high heat input electro-slag welding(ESW) of Ti-Zr micro-alloyed high strength steel were studied in this paper.Both the HAZs had excellent strength and toughness under different welding heat inputs,and acicular ferrite is the dominant microstructure in both HAZs.The microstructures were coarser and a small quantity of M-A microstructures existed uniformly in HAZ of ESW,the second phase inclusions were Ti,Zr and Mn containing complex oxide under different welding heat inputs,and the inclusions were relatively smaller and numerous in the simulated welding HAZ,remarkably promoting the nucleation of intra-granular acicular ferrite.