Haynes 282焊丝的焊接冶金分析及性能研究

Welding Metallurgy Analysis and Property of Haynes 282 Welding Wire

对Haynes282焊丝进行了热力学模拟计算,得到了其热力学稳态相和热物性参数等。Haynes282熔敷金属热力学稳态相包括γ基体、γ’、MC、M6C、M23C6、σ相,但根据模拟计算的熔敷金属连续冷却转变曲线和等温转变曲线,焊态下熔敷金属只有一次MC碳化物在凝固过程中析出。采用钨极氩弧焊进行堆焊,对焊丝熔敷金属进行表征。结果表明:凝固过程中由于Mo、C、Ti元素强烈向枝晶间偏析,导致凝固末期在枝晶间形成了一次Mo6C相,焊丝熔敷金属中并无σ等有害相析出,焊丝熔敷金属室温的硬度和冲击韧性分别为300 HV和140 J/cm2。采用大的焊接热输入和较小角度坡口,焊道中出现了结晶裂纹,与模拟计算得到的焊丝熔敷金属凝固末期粘度和膨胀系数较大相一致,说明该焊丝对结晶裂纹存在一定敏感性。

The equilibrium phase and thermal physical property of Haynes 282 welding wire were obtained by thermodynamic calculation. The γ, γ’, MC, M6C, M23C6, σ phase were equilibrium phases of HAYNES 282 filler metal. But there was only primary MC phase in the as-welded deposited metal according to the simulated CCT and TTT diagram. The surfacing welding was carried out by TIG welding, and the deposited metal of the welding wire was characterized. The results show that the primary Mo6C phase precipitates between dendrites because of the interdendritic segregation of Mo,C, Ti, and there is no harmful phase precipitation such as σ phase. The hardness and impact toughness of as-welded deposited metal at room temperature are 300 HV and 140 J/cm2 respectively. When the high welding heat input and small angle groove are adopted,solidification cracks appear in the weld, which coincides with the large viscosity and thermal expansion coefficient of the deposited metal obtained by the simulation. It shows that the welding wire is sensitive to solidification crack in some extent.