Corrosion-resistant metallurgical composite bimetal longitudinal submerged-arc welded steel pipe and method for manufacturing same

Abstract

The invention provides a corrosion-resistant composite bimetal longitudinal submerged-arc welded steel pipe and a method for manufacturing the same. The method includes steps of (1), manufacturing bimetal composite steel plates by a hot rolling process; (2), carrying out edge milling, pre-bending, JCO forming and pre-welding on the bimetal composite steel plates manufactured in the step (1); (3), welding weld joints of a steel pipe by a submerged-arc welding process, particularly, welding a carbon steel layer of a base layer at first when the weld joints are welded, and then welding metal of a clad layer of a corrosion-resistant layer. The steel pipe is obtained after JCO forming and pre-welding are carried out on the bimetal composite steel plates. The corrosion-resistant composite bimetal longitudinal submerged-arc welded steel pipe and the method have the advantages that the corrosion-resistant metallurgical composite bimetal longitudinal submerged-arc welded steel pipe is manufactured by a hot rolling metallurgical composite bimetal steel plate and JCOE pipe manufacturing process and the efficient automatic submerged-arc welding process, double layers of metal of the steel pipe can be metallurgically combined with each other, and accordingly the steel pipe is high in strength, integrity and corrosion resistance; the JCOE pipe manufacturing process is adopted, so that the steel pipe is high in mechanical degree, production efficiency and overall dimensional accuracy, and steel pipes with the lengths of 12 meters can be produced by the method.

Description

technical field [0001] The invention belongs to the field of metal machining, and in particular relates to a corrosion-resistant metallurgical composite bimetal straight seam submerged arc welded steel pipe and a preparation method. Background technique [0002] At present, corrosion-resistant bimetallic straight seam welded steel pipes are mainly mechanical composite steel pipes. The so-called mechanical composite bimetallic welded steel pipes are made of base steel pipes (seamless or welded steel pipes in which the base steel pipes are carbon steel or low alloy steel pipes) and clad steel pipes. (The cladding steel pipe is welded steel pipe of stainless steel or nickel-based alloy), and then put the base steel pipe on the cladding steel pipe, and use mechanical methods such as mechanical expansion, mechanical spinning, hydraulic pressure or blasting to make the two pipe surfaces stick together. For example, patent CN102794601A discloses a manufacturing method of bimetallic...

AI Technical Summary

Problems solved by technology

Although the welding process of the base layer and the cladding steel pipe is relatively simple for this kind of mechanical composite steel pipe, the bonding strength of the bimetallic bonding surface is low, and the bonding surface is often mixed with some rust and iron oxide due to unclean treatment. and other stolen goods, and it is also easy to produce gaps. At the same time, due to uneven mechanical pressure or blasting impact force, the thickness of the corrosion-resistant layer will be uneven. These problems will affect the service life and corrosion resistance of the steel pipe.

This also limits the application in major occasions

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