板厚对Ti60钛合金电子束焊接头显微组织及力学性能的影响

Influence Of Plate Thickness On Microstructure And Mechanical Properties Of Electron Beam Welding Joint Of Titanium Alloy Ti60

摘要:

研究了不同厚度Ti60钛合金板材电子束焊接接头的显微组织与力学性能。研究结果表明,不同厚度Ti60合金板材的焊接接头均由熔合区、热影响区和母材区组成,熔合区由粗大的柱状晶组成。板材厚度对柱状晶内部显微组织影响很小,不同厚度的板材熔合区柱状晶内的显微组织相似,均由细小的片层α相和少量β相组成,不同厚度的板材电子束焊接接头熔合区均具有较高的硬度和强度。700℃焊后热处理会使熔合区α相的边界处析出大量的硅化物。

Abstract:

Microstructural evolution and mechanical properties of the election beam weldments of different thickness Ti60 titanium alloy plates were investigated in this study. Metallographic examination of as-welded Ti60 electron beam welds showed that there exhibited three zones in the EBW weldments, the fusion zone (FZ), heat affected zone (HAZ), and base metal (BM). The fusion zone was consisted of columnar grains. Effect of plate thickness on the microstructure of columnar grains is small. So the microstructure of columnar grains of different thickness plate was similar and was consisted of fine α plates and a small amount of β phase. The micro-hardness and the strength of the fusion zone was higher than the base metal. For the fusion zone, a large number of silicide precipitated in the boundary of α phase after the post weld heat treatment (PWHT) at 700℃.