Formation of the structure of titanium and stainless steel in laser welding

Features of the structural phase state of a weld produced by electron-beam welding in the submicrocrystalline grade 2 titanium alloy

“…In the PM zone, the titanium alloy is in the singlephase state with the -phase. This finding correlates with the data in [1]. According to Xray diffraction data, the -phase is found to have a hexagonal close-packed lattice with parameters а = 0.29761 nm and с=0.47367 nm.…”

“…2 c, d): large polyhedral grains of the transformed β-phase with an average grain size of 60  90 μm and a plate-like intragranular structure of the α-phase. A similar structure was observed in [1] when welding a titanium alloy in a weld after laser welding. Structural changes induced by laser welding of the Grade 2 titanium alloy led to a slight increase in the average microhardness value in the weld zone [1].…”

“…A similar structure was observed in [1] when welding a titanium alloy in a weld after laser welding. Structural changes induced by laser welding of the Grade 2 titanium alloy led to a slight increase in the average microhardness value in the weld zone [1]. In our case, the HAZ microstructure induced by electron beam welding ( Fig.…”

“…5). These microhardness values far from the weld joint are typical of the Grade 2 titanium alloy in the corresponding structural states [1,10,12,14]. The above microhardness distributions depending on distances in the base metal zone far from the welded joint clearly show that the microhardness of the microcrystalline alloy at the center of the weld joint (lines 2 and 3, Fig.5) has a smaller spread of values as compared to the alloy in the submicrocrystalline state, while average microhardness values in both states are close to each other.…”

“…In this context, laser welding is the most frequently discussed technology [1][2][3][4]. Its advantage is the possibility of welding in the atmosphere rather than in vacuum as in the case of electron-beam welding [5,6].…”