By taking molybdenum (Mo) having favorable metallurgical compatibility with both titanium and iron as the interlayer material, the butt joint of TA1/Q235B layered bimetallic sheet with thickness of 6 mm was prepared by utilizing narrow gap multi-pass laser welding with low heat input. Mo generally can favorably isolate Ti from Fe, meanwhile the transition zone of Mo and steel adjacent to Mo interlayer was softened according to the results of microhardness test. The results of face bending testing showed that the softened zone was beneficial to the mechanical properties of the welded joint, which could restrict the crack propagation along the interface of Mo/steel in fusion zone so that fracture appeared in the BM side. The microstructures of the softened zone exhibited a low dislocation density observed by a transmission electron microscope (TEM), which may be the main reason leading to a low microhardness. In additon, Mo interlayer was confined in a small zone, which only accounted for about 6.5% of the total area of cross section of the fusion zone while a small amount of FeTi and λ brittle intermetallic compounds (IMCs) still appeared around the Mo/steel interface in fusion zone. The tensile strength of the welded joint was 467 MPa, which took up about 93% that of base metal. The results of this paper will help guide endeavours for the fabrication of pipes and containers made of Ti/steel bimetallic sheets.

以与钛和铁均具有良好冶金相容性的钼（Mo）为中间材料，利用低间隙多道缝低通量激光焊接制备了厚度为6 mm的TA1 / Q235B层状双金属薄板的对接接头。 。Mo通常可以很好地将Ti与Fe隔离开来，同时根据显微硬度测试的结果，Mo和与Mo中间层相邻的钢的过渡区被软化了。面弯曲试验结果表明，软化区有利于焊接接头的力学性能，可能会限制熔合区中沿Mo /钢界面的裂纹扩展，从而使BM侧出现断裂。通过透射电子显微镜（TEM）观察到，软化区的微观结构显示出低位错密度，这可能是导致显微硬度低的主要原因。此外，Mo夹层被限制在一个小区域内，仅占熔融区域横截面总面积的约6.5％，而少量的FeTi和λ脆性金属间化合物（IMC）仍出现在Mo /附近熔合区中的钢界面。焊接接头的抗拉强度为467 MPa，约占贱金属的93％。本文的结果将有助于指导由Ti /钢双金属板制成的管道和容器的制造工作。熔融区横截面总面积的5％，而熔融区Mo /钢界面周围仍出现少量FeTi和λ脆性金属间化合物（IMC）。焊接接头的抗拉强度为467 MPa，约占贱金属的93％。本文的结果将有助于指导由Ti /钢双金属板制成的管道和容器的制造工作。熔融区横截面总面积的5％，而熔融区Mo /钢界面周围仍出现少量FeTi和λ脆性金属间化合物（IMC）。焊接接头的抗拉强度为467 MPa，约占贱金属的93％。本文的结果将有助于指导由Ti /钢双金属板制成的管道和容器的制造工作。