42CrMo/GH4169异种金属惯性摩擦焊工艺

Inertial friction welding process of 42CrMo/GH4169 dissimilar metals

主要采用惯性摩擦焊技术对中碳调质钢42CrMo和镍基高温合金GH4169进行连接成形,借助光学电子显微镜、扫描电镜、能谱分析仪、显微硬度仪及电子拉伸试验机研究不同惯量条件下的焊接接头的微观组织和力学性能。结果表明,当惯量为168 kg·m^(2)时,42CrMo和GH4169惯性摩擦焊接头飞边成形较好,去除飞边后无明显缺陷;焊缝界面两侧区域均发生动态再结晶,且观察到了5μm厚的不均匀金属间化合物(Ni-Fe-Cr,Ni_(3)Al)和碳化物层(NbC,TiC),这就使得焊缝界面处的显微硬度峰值达691 HV1.0;通过接头拉伸性能试验,168 kg·m^(2)惯量下的试样室温拉伸和高温拉伸(540℃)断裂位置均发生在42CrMo母材侧,断口形貌观察为典型的韧性断裂,室温抗拉强度达1062.5 MPa,高温抗拉强度达687.5 MPa,均与42CrMo母材相当,这说明了界面处形成的金属间化合物和碳化物层促进了接头界面材料的冶金结合,有效的提高了焊接接头的力学性能。

Inertia friction welding technology was mainly used to connect medium carbon quenched and tempered steel 42CrMo with nickel base superalloy GH4169.Microstructure and mechanical properties of welded joints under different inertia were analyzed by means of optical electron microscope,scanning electron microscope,energy spectrum analyzer,microhardness tester and electronic tensile tester.The research results showed that when inertia was 168 kg·m^(2),flash of 42CrMo and GH4169 inertial friction welded joints was well formed,and there was no obvious defect after flash was removed.Dynamic recrystallization occurred on both sides of weld interface,and uneven intermetallic compounds(Ni-Fe-Cr,Ni_(3)Al)and carbide layers(NbC,TiC)with thickness of 5μm were observed,which also resulted in microhardness peak of 691 HV1.0 at the weld interface.According to tensile property test of welded joints,fracture location of samples under 168 kg·m^(2) at room temperature and high temperature tensile(540℃)occurred on the 42CrMo base metal side.Fracture morphology observation showed typical ductile fracture,tensile strength at room temperature reached 1062.5 MPa,and tensile strength at high temperature reached 687.5 MPa,which were similar to 42CrMo base metal.This indicated that intermetallic compounds and carbide layers formed at the interface promoted metallurgical bonding of interface materials,and effectively improved mechanical properties of welded joints.