Method for expanding titanium T-shaped pipe

Abstract

The invention relates to a method for processing a metal pipe, in particular to a bulging method for a titanium T-shaped pipe. The method comprises the following steps of: blanking and preparing a copper alloy coating layer with the thickness of 2-10 mum and a molybdenum sulfide coating layer with the thickness of 50-200 mum on the surface of a blank, wherein the unit bulging force C of the pipe in the hydraulic molding is equal to 1.35-1.6; bulging many times, annealing, machining and carrying out surface treatment and then obtaining a product. The invention adopts a composite lubricating agent, reduces the friction between the pipe blank and a die during bulging, solves the molding problem of a high-quality thin wall titanium pipe for warship and aviation industries, protects the die and prolongs the service life of the die, and allows industrial bulk production of the high-quality thin wall titanium T-shaped pipe for industries, such as warships, aviation, and the like, to be realized. The quality of the product reaches the advanced level of international congeneric products, which changes the passive situation that the product relies on foreign import for a long time.

Description

technical field [0001] The invention relates to a processing method for a metal pipe fitting, in particular to a bulging method for a titanium T-shaped pipe fitting. Background technique [0002] Titanium is light in weight and high in strength, and has excellent resistance to various corrosions. It is an ideal material for aviation, aerospace, ships and chemical industries. In recent years, with the continuous enhancement of my country's comprehensive strength, the amount of titanium used increasing day by day. Such materials are widely used in seawater piping systems of ships, especially in seawater piping systems of various modern submarines, as well as strong acids, strong alkalis and salt production in the chemical industry. [0003] Due to the high specific strength of titanium, poor plasticity at room temperature, stickiness, and large friction coefficient, the conventional production method can only choose the insertion welding or hot drawing process, which is differ...

AI Technical Summary

Problems solved by technology

When the titanium pipe fittings are produced by the insertion welding process, because the weld seam of the pipe fittings is at a right angle, it is easy to produce local corrosion and cause pipeline leakage; in addition, when the titanium T-shaped pipe fittings are produced by the hot drawing process, the final surface quality of the pipe fittings is limited by the production process. And it is only suitable for making various pipe fittings with thicker wall thickness. It is easy to wrinkle and cannot be formed when producing thin-wall pipe fittings

Therefore, the general thin-walled titanium T-shaped pipe fittings required in the non-key parts of the actual project are all processed into thick-walled titanium T-shaped pipe fittings with thick-walled pipes, and then the end of the pipe fittings is processed and beveled for use. The disadvantages of high cost and low comprehensive quality limit the application of this product in the fields of aviation, spaceflight, shipbuilding and chemical industry.

In the past, high-quality titanium T-shaped pipe fittings for domestic aviation and ships were imported from abroad, and the processing methods of such products abroad have not been reported.

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