Welding method for thin-walled titanium alloy spherical member

Abstract

The invention discloses a welding method for a thin-walled titanium alloy spherical member. The welding method is applied to a thin-walled titanium alloy spherical member; the spherical member comprises an upper hemispherical housing, a lower hemispherical housing, a connecting disc, a flange and a joint which are made of a titanium alloy material; the method comprises the following steps of: pre-processing the upper hemispherical housing, the lower hemispherical housing, the connecting disc, the flange and the joint; assembling the pre-processed upper and lower hemispherical shousings, connecting disc, flange and joint to obtain a spherical member; fixing the spherical member to a welding tool of a specific back inflation protection device, and introducing protective gas into the back inflation protection device to make sure that the oxygen content in a cavity of the back inflation protection device is lower than a preset threshold value; and conducting spot fixation on the joint weldseams concentrated according to stress in sequence from the inner ring to the outer ring, and conducting welding in a pulse-modulated laser swing welding mode according to the spot fixation sequence.The welding method disclosed by the invention solves the technical problem about relatively poor reliability of welding of thin-walled titanium alloy spherical members in the prior art.

Description

technical field [0001] The present application relates to the field of welding technology, in particular to a welding method for thin-walled titanium alloy spherical components. Background technique [0002] With the application and development of aerospace technology, higher and higher requirements are put forward for the storage and effective supply of fuel in the outer space of the atmosphere. Titanium alloy thin-walled spherical components, as the key components to realize the above functions, have the characteristics of high bearing pressure and small deformation. The main structure of the titanium alloy thin-walled spherical member is composed of upper and lower shells and flanges. The thinnest part of the girth weld on the sphere is 0.9mm, and the thickest part is 2.4mm. There are both bottom-locked butt joints and butt joints. By means of welding, the upper and lower shells and flanges are connected to form spherical components, which can realize the storage and eff...

AI Technical Summary

Problems solved by technology

[0003] The technical problem solved by this application is: Aiming at the problem that the reliable connection of titanium alloy thin-walled spherical components cannot be realized in the prior art, this application provides a welding method for thin-walled titanium alloy spherical components. The solution provided by the embodiment of this application Among them, on the one hand, the protective gas is filled into the back inflatable protection device so that the oxygen content in the cavity is lower than the preset threshold value, that is, the preset threshold value corresponding to the set oxygen content can be adjusted so that the cavity of the thin-walled titanium alloy spherical member The oxygen content in the body meets the actual welding needs, avoiding the oxidation of the thin-walled titanium alloy spherical weld during the welding process, which affects the quality of the weld; on the other hand, the pulse-modulated laser swing welding method is used for welding, not only The parameters of the laser are dynamically adjusted to avoid the heat accumulation caused by the output of continuous high-power laser, and the spatter of the thin-walled titanium alloy spherical member is avoided, so that the weld surface is well protected, well-formed, without undercuts, pits and other defects, and also The swing welding method can be used to avoid more pores in the weld seam, thereby improving the quality of the weld seam and the comprehensive mechanical properties, so that the overall deformation of the spherical member product is small and the pressure bearing capacity is good

Images