摘要
使用CO2气体保护焊和手工电弧焊对16 mm厚的440 MPa级海洋工程用钢板进行了对接试验,对比了两种焊接方法下焊接接头的组织和力学性能。结果表明,CO2气体保护焊焊缝组织主要为针状铁素体、侧板条铁素体和少量残余奥氏体,而手工电弧焊的焊缝组织主要为针状铁素体、粒状贝氏体以及少量残余奥氏体,两者热影响区粗晶区组织均为板条结构;气体保护焊焊缝的硬度低于手工焊的,且其接头硬度分布更不均匀;相对于手工电弧焊,气体保护焊焊缝强度较高,塑性较差,-40℃下的冲击功远低于手工电弧焊的;两者冲击断口均为准解理断口形貌,但手工焊断口有许多延性脊,改善了韧性。
The butt welding tests of 440 MPa grade marine engineering steel plate with thickness of 16 mm were carried out by using CO2 gas shielded arc welding and manual arc welding. The microstructure and mechanical properties of the welded joints under the two welding methods were compared. The results show that the weld microstructure of CO2 gas shielded welding is mainly acicular ferrite, side lath ferrite and a small amount of retained austenite, while the weld microstructure of manual arc welding is mainly acicular ferrite, granular bainite and a small amount of retained austenite. The microstructure of the two coarse grain heat affected zones is slab structure. The weld hardness of gas shielded arc welding is lower than that of manual arc welding, and the hardness distribution of the welded joint is more uneven. Compared with manual arc welding, the weld of gas shielded arc welding has higher strength and poorer plasticity, and the impact energy at -40℃ is much lower than that of manual arc welding. Both the impact fractures are quasi cleavage fracture, but there are many ductile ridges in the manual welding fracture, which improves the toughness.
出处
《热加工工艺》
CSCD
北大核心
2018年第1期75-78,87,共5页
Hot Working Technology
关键词
440MPa级海洋工程用钢
焊缝
热影响区粗晶区
冲击断口
440 MPa grade marine engineering steel
welding seam
coarse grain heat affected zone
impact fracture
