Ti52钛合金/304不锈钢异种材料惯性摩擦焊接技术研究

Study on Inertial Friction Welding Technology of Ti52 Titanium Alloy/304 Stainless Steel Dissimilar Materials

采用惯性摩擦焊接技术对Ti52钛合金/304不锈钢进行连接,借助光学显微镜、扫描电镜及能谱分析仪对两种焊接工艺参数的焊后接头组织和界面金属间化合物进行表征和分析,采用显微硬度仪及电子拉伸试验机进行力学性能验证。结果表明,近界面两侧焊缝组织均发生了动态再结晶,导致焊缝区附近显微硬度值较高,越远离焊缝位置显微硬度值越低,Ti52合金侧远离焊缝位置出现显微硬度峰值为450 HV0.5,是由于热力耦合作用下组织发生破碎细化。高热输入、低焊接压力下,焊接界面形成厚5μm且不均匀的金属间化合物脆性相Ti/FeTi,不利于钛/钢结合,降低接头性能,抗拉强度159 MPa;低热输入、高焊接压力下,焊接界面中心部位形成厚2μm且均匀的富Cr金属间化合物Ti5Fe17Cr5,有利于接头界面结合,提高接头性能,抗拉强度为350 MPa。

The inertia friction welding technology to connect Ti52/304 stainless steel/titanium alloy,explore under two kinds of welding process parameters,by means of optical microscope,scanning electron microscopy(sem)and energy spectrum analyzer after butt welding joint organization and interface intermetallic compound were characterized and analyzed by means of microhardness meter and electronic tensile testing machine for mechanical properties test and verify.The results show that dynamic recrystallization occurs on both sides of the weld near the interface,resulting in a high microhardness value near the weld zone,and the microhardness value decreases continuously as the distance from the weld site is increased.The peak microhardness value of Ti52 alloy far from the weld site is at 450 HV0.5,which is due to the microstructure fragmentation and refinement under the action of thermodynamic coupling.At high heat input and low welding pressure,the brittle phase Ti/FeTi with thickness of 5μm and inhomogeneity is formed at the welding interface,which is not good for the bonding of titanium steel and reduces the joint properties,the tensile strength is 159 MPa.Under low heat input and high welding pressure,the cr-rich intermetallic compound Ti5Fe17Cr5 with uniform thickness of 2μm is formed at the center of the welding interface,which is beneficial to the joint interface bonding and improves the joint properties,the tensile strength is 350 MPa.