End socket structure of copper and steel bimetallic pipe and seal welding method thereof

Abstract

The invention discloses an end socket structure of a copper and steel bimetallic pipe and a seal welding method thereof; and the end socket structure comprises a copper pipe and a steel pipe which are connected at the combining place of end sockets by a diffusion welding combining layer. The seal welding method comprises the following steps of: cleanly washing surfaces of the copper pipe end socket and the steel pipe end socket to be combined, and gluing the combining surfaces in advance; pressing an expanding plug into an inner hole of the copper pipe end socket; putting the copper pipe end socket and the steel pipe end socket into a diffusion annealing furnace filled with protective gas for heating and thermal insulation so that atoms of the copper and the steel mutually diffuse under the combined action of interference deformation force and temperature, discharging and air cooling, and dropping out the expansion plug. As the invention does not use an expensive silver-bearing welding material and a complex welding technology and only uses simple plastic deformation and the expansion plug, compared with the prior art, the end socket structure and the seal welding method have simple process and low cost and realize reliable welding seal between the cooper and the steel, and no crack is generated in end seams.

Description

technical field [0001] The invention relates to a sealing welding technology for a bimetallic pipe end, in particular to a copper-steel bimetallic pipe end structure and a sealing welding method thereof. Background technique [0002] Copper-steel bimetallic pipe is a kind of composite pipe, which not only has the high strength and cheapness of the outer steel pipe, but also has the corrosion resistance and excellent thermal conductivity of the inner copper pipe, such as water pipes, hot water exchange The tubes are very suitable. [0003] Although from the perspective of material weldability, steel and copper are not unweldable, but the weldability is very poor. In order to obtain a reliable welded joint, special welding methods or welding materials are often required to achieve it. [0004] Chinese patent ZL200710156981.9 discloses a "gas shielded welding wire for mutual welding of copper and iron". A gas-shielded welding wire for mutual welding of copper and iron. Its te...

AI Technical Summary

Problems solved by technology

[0012] Due to the poor weldability between copper and steel, cracks are prone to occur in the weld seam, resulting in unreliable sealing, and none of the above technologies has solved the problem of reliable sealing welding of the copper-steel bimetallic pipe end structure

Images