Research On Electron Beam Welding Of TC4 Titanium Alloy And 304 Stainless Steel

In this paper, aiming at difficult problems of welding of TC4 titanium alloy and 304 stainless steel, such as:easy to crack, deformation and other difficult issues, electron beam welding of 304 stainless steel and TC4 titanium alloy was carried out. we study the welding process, the joint performance by using different middle layer, the distribution of elements and organization of the joint, and provide a new way for the welding of titanium alloy and stainless steel.Because it is difficult to achieve the two connections of TC4 titanium alloy and 304 stainless steel by direct electron beam welding, this paper studies the use of vanadium and vanadium-copper composite middle layer as the middle layer to welding of titanium and steel. Experiments show that:The connection of Vanadium with TC4 and 304SS are good. Vanadium can be used as intermediate layer to weld titanium alloy and stainless steel. The good welding metallurgy of vanadium and iron, titanium and vanadium can be seen from the Phase diagram. The analysis of the distribution of elements from the scanning electron microscope was showed that Vanadium layer can block the combination of elements that was easy to form intermetallic compounds, such as:titanium, iron and others. When using the different width of the vanadium layer and the parallel welding method, the strength of the transition joints with the wide vanadium layer exceeded 283MPa. And when using the thin middle layer, two weld was easy to access together and produce intermetallic compounds that lead to weld cracking. When using two welding in relative method, It can reduce the use of vanadium layer. The 0.1-0.2mm pure vanadium area was appeared between the two weld joints at begin of the welding parts of the joints by using a 0.9mmV, The plastic deformation of the joints was restricted by tensile triaxial stress at this time, so the high intensity of 480Mpa has been get at the beginning of the welding area. The disadvantage of using an intermediate layer was avoided by adding the middle layer of copper and vanadium. And a certain strength welded joints of TC4 and 304SS was gained and provided methods and theoretical guidance.of getting high strength and low-cost high-quality joints of titanium alloy and stainless steel.