大线能量焊接用FH500高强船板钢的研制与焊接试验

采用复合微合金化的成分设计,通过TMCP(热机械处理)工艺开发了适应大线能量焊接的FH500高强船板钢。运用埋弧焊和垂直气电立焊对FH500船板钢进行了焊接试验,对两种焊接方式的焊接接头分别进行了拉伸、弯曲、冲击等力学试验,研究了不同热输入值对接头力学性能的影响;运用透射电镜对焊接热影响区组织析出物进行了分析。结果表明:FH500高强船板钢组织以针状铁素体为主,具有良好的强韧性匹配;两种焊接方式接头力学性均能满足船级社标准。焊接热影响区(HAZ)组织为针状铁素体和贝氏体组织,晶内含有大量纳米级析出物,能谱显示,其成分为钛铌的复合析出物。

Preparation and high input welding of a FH500 ship plate steel

A micro-alloy FH500 high strength ship plate steel was developed successfully by alloying design and thermo-mechanical controlled process(TMCP) for high input welding in laboratory.Welding performance of the FH500 ship plate steel was examined by submerged-arc welding and vertical gas electricity welding test.Mechanical properties of weld joints were investigated by means of impact test,tensile and bending tests.The influence of different heat input values on the properties was studied,and the precipitates in heat affect zone of the weld joint were analyzed by transmission electron microscopey(TEM).The results indicate that microstructure of the FH500 high strength ship plate steel consists of mainly ferrite exhibiting a good combination of strength and toughness.The mechanical properties of the two kinds of weld joints are satisfied to requirement of ship building.The microstructure of HAZ is composed of ferrite and bainite with a number of nano-precipitates in the grains.Energy spectrum analysis shows that the precipitates are compound of titanium and niobium.