【摘要】 过渡液相扩散连接技术（TLP）是一种综合了钎焊和扩散焊优势的先进连接方法。以U75V钢轨钢为母材，石墨纸为中间层，采用TLP方法进行焊接，研究了在焊接温度1 200℃、焊接压力0.5 MPa、保温时间5 min条件下焊接接头的组织演变规律。通过金相分析、显微硬度测试和准静态拉伸等分析测试方法，对U75V钢轨钢TLP焊接接头的力学性能进行了研究。结果表明：在该焊接条件下，Fe-C共晶反应可有效去除氧化膜并改善润湿效果，通过C原子的间隙扩散及等温凝固过程实现了接头组织均匀化。所得接头抗拉强度达到804 MPa，为母材强度的76.6%。更多还原

【Abstract】 Transient Liquid Phase Bonding(TLP) is an advanced joining method integrating the benefits of brazing and diffusion welding. U75V rail steel was joined via TLP method with graphite paper as the interlayer. The microstructure evolution of the welded joint was investigated under the bonding conditions of 1 200 ℃, 0. 5 MPa pressure, and a holding time of 5 min. The mechanical properties of the TLP welded joint bonded U75V rail steel joints were investigated using metallographic analysis, microhardness testing, and quasi-static tensile testing. The results demonstrate that under these bonding conditions, the Fe-C eutectic reaction effectively achieves oxide removal and wetting effects, while the interstitial diffusion of C atoms and isothermal solidification process promote microstructural homogenization in the joint. The tensile strength of the joint reached 804 MPa, achieving 76. 6% of the base metal’s strength.更多还原