Heat Treatment Process of Straight Seam Steel Pipe

How to heat treatment of straight seam steel pipe?

First of all, the mold should be planned reasonably, the thickness should not be too wide, and the shape should be symmetrical. For molds with larger deformations, the deformation laws should be mastered and the machining allowance should be reserved. For large, precise and messy molds, combination planning can be selected. Heat treatment, aging heat treatment and tempering nitriding heat treatment to control the precision of the mold. When repairing mold sand holes, pores, wear and other defects, use cold welders and other correction equipment with low thermal influence to avoid deformation in the repair process. Pre-heat treatment of the precision messy mold eliminates the stress attack of the rest of the machining process. For precision fluffy molds, vacuum heating quenching and cryogenic treatment should be selected as much as possible. On the premise of ensuring the hardness of the mold, try to choose the pre-cooling, graded cooling quenching or temperature quenching process.

The forming methods of straight seam steel pipes include UOE forming method, roll forming method (CFE), CE forming, etc. For most forming methods, the last process is to expand the full-length diameter of the welded pipe billet again to improve the shape of the welded steel pipe. , Diameter expansion has become an important process in the production of longitudinal welded pipes to ensure finished pipes. The mechanical method is simpler and more efficient than the hydraulic method. Several types of straight seam welding control pipelines are used internationally.

1. The initial round stage. The sector blocks are opened until all sector blocks are in contact with the inner wall of the steel pipe. At this time, the radius of the round pipe in the steel pipe is almost the same within the step size range, and the steel pipe reaches the initial circle.

2. Nominal inner diameter level. The sector block starts from the front until it reaches a predetermined position, which is the circumferential position required for the finished tube.

3. Flexible recovery and compensation stage. The position of the sector block in the second stage will be further lowered until it reaches the required position, that is, the circumferential position of the elastic front steel pipe required by the process design.

Thick-walled spiral pipe is better than ordinary spiral pipe in mechanical properties such as compression and tension. In engineering, high requirements are put forward for the use of spiral pipes. The reason why thick-walled spiral pipes appears is because the pressure generated by some media to be transported is unbearable for ordinary spiral pipes. If it is replaced with straight seam or seamless steel pipe, the project cost will be greatly increased. Spiral seam arc welded pipes for ordinary fluid conveying pipes. Part of technical requirements for steel pipe transportation in liquefied petroleum gas industry: steel pipe. The rust removal speed of the spiral steel pipe depends on the type of abrasive and the displacement of the abrasive. Generally, the abrasive with low loss rate should be selected, which is beneficial to improve the cleaning speed and long blade life. Pay attention to the importance of surface treatment in production, and strictly control the process parameters when removing rust. In actual construction, the peeling strength of the steel pipe anticorrosive layer greatly exceeds the standard requirements, ensuring the anticorrosive layer. On the basis of the same equipment, the process level is greatly improved and the production cost is reduced.

Tips: ASTM A53 covers seamless and welded steel pipe with nominal wall thickness. The surface condition is usually black and hot-dipped galvanized. ASTM A53 is produced mainly for pressure and mechanical applications, and is also used for transport of steam, water, gas line pipes.
ASTM A53 Grade B is the material under the American steel pipe standard, API 5L Gr.B is also the American standard material, A53 GR.B ERW refers to the electric resistance welded steel pipe of A53 GR.B; API 5L GR.B Welded refers to the material Welded steel pipe of API 5L GR.B.

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