Stainless steel compound welding steel pipe and manufacturing method thereof

Abstract

The invention discloses a stainless steel compound welding steel pipe and a manufacturing method thereof. The stainless steel compound welding steel pipe is formed by welding stainless steel compound hotly-rolled rolling plates through a welding line, wherein the welding line is formed by a stainless steel compound welding line and a carbon steel welding line. The manufacturing method comprises the following steps of: milling an edge and arranging a groove; when putting a stainless steel compound layer on the inner layer, firstly utilizing gas shield welding to weld a middle layer; then, utilizing a stainless steel welding strip to weld a stainless steel compound layer welding line in an argon arc welding manner; then, utilizing a carbon steel welding strip to weld the carbon steel welding line by a submerged-arc welding manner; when the stainless steel layer is less than 0.9 mm, directly welding a stainless steel welding line by submerged-arc welding; and when the stainless steel compound layer is located at the outer layer, firstly welding the carbon steel welding line by adopting the carbon steel welding strip and the submerged-arc welding, and adopting the stainless steel welding strip and the argon arc welding manner to weld the stainless steel compound layer welding line. According to the stainless steel compound welding steel pipe and the manufacturing method thereof, the manufactured stainless steel compound welding steel pipe has high structural strength and strong corrosion resistance; and the bonding strength of an inner pipe and an outer pipe is not less than 200 MPa.

Description

technical field [0001] The invention relates to the technical field of steel pipe manufacturing, and more specifically relates to a stainless steel composite welded steel pipe and a manufacturing method thereof. Background technique [0002] During the construction of many projects such as municipal construction and vehicle and ship manufacturing, it is inevitable to use many pipelines, such as direct drinking water pipelines, engineering hot and cold water pipelines, heating pipelines, sewage treatment pipelines, gas pipelines, negative pressure pipelines, etc. Now Some of these pipes use plastic pipes, which are cheap and have good corrosion resistance, but their structural strength is not high enough and are easy to break and damage; some use carbon steel pipes, which have high structural strength, but, Its corrosion resistance is poor, and it is often corroded and worn out after a certain number of years of use. Some use stainless steel pipes. Stainless steel pipes have ...

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Problems solved by technology

However, the diameter of the stainless steel clad steel pipe in this way is not large enough, and the bonding strength between the stainless steel pipe and the carbon steel pipe is not high enough.

The Chinese invention patent with the publication number CN101085455 and the publication date of December 12, 2007 discloses a method for manufacturing a spiral composite steel pipe. In its patent document, it uses internal welding and external welding to weld stainless steel composite steel pipes, so that In the welding method of the stainless steel pipe, it is inevitable that a part of the carbon steel will penetrate into the stainless steel liquid, so that the corrosion resistance of the stainless steel pipe formed after welding is poor, and the structural strength of the whole composite steel pipe is not high enough.

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