摘要
The feasibility of dissimilar friction stir welding(FSW)between the SAF 2507 super duplex stainless steel and the Incoloy825 Ni-based superalloy was evaluated.The microstructure and mechanical behavior of the weldments were examined too.The results showed that the alloys were successfully welded together by positioning the SAF 2507 on the advancing side.The nuggets displayed higher hardness than the base metals,due to the occurrence of dynamic recrystallization and the subsequent refinement of the microstructures.The welded sample obtained the similar strength to the Incoloy 825 parent metal,showing the ductile fracture mode after the tensile tests by SEM.Moreover,the weld zone(31 J)exhibited higher and lower toughness than the Incoloy 825(23 J)and SAF 2507(42 J)parent metals,respectively.Based on the obtained results,the FSW method could be recommended to weld the super duplex stainless steel/Ni-based superalloy joints.
研究SAF 2507超级双相不锈钢和Incoloy 825镍基超合金间使用异种搅拌摩擦焊(FSW)的可行性,检测焊缝的显微组织和力学行为。结果表明,通过将SAF 2507定位在前进侧,可以将两种合金成功焊接在一起。由于熔核发生动态再结晶,以及熔核显微结构的细化,熔核的硬度高于基体硬度;所得焊接样品具有与Incoloy 825母合金相近的强度;SEM观察拉伸测试后的样品显示,其断裂模式为韧性断裂,焊缝区的断裂韧性(31 J)比Incoloy825母合金的(23 J)高,而比SAF 2507母合金的(42 J)低。基于以上结果可知,FSW方法适用于焊接超级双相不锈钢/镍基超级合金接头。
