Carbon steel straight seam pipe
Carbon steel straight seam pipe is an opposite welding technology of spiral steel pipe. The welding process of this kind of steel pipe is relatively simple, and the welding cost is relatively low, so it can achieve higher efficiency in production, so it is common in the market. This kind of steel pipe is welded by the welding method parallel to the longitudinal of the steel pipe, and it is also widely used. Same diameter and same length. The welding length of straight joint steel pipe is much less, while the welding length of spiral steel pipe may increase by more than 30%. Due to the process, the efficiency is low and the output is quite low. However, for the same billet, products of various diameters can be obtained by spiral welded tubes in general. By contrast, straight - seam steel tubes cannot achieve this welding effect.
Carbon steel straight seam pipe is widely used in the market. Because of its unique characteristics. Because the process cost used in welding is relatively low, and the use of forged steel, extrusion, rolling and drawing steel production process can be manufactured, and the specification is determined, so for a wide range of applications to provide the possibility. In petrochemical industry, water engineering industry, urban construction, power engineering and so on, there is a demand for straight seam steel pipe.
The main production process of Carbon steel straight seam pipe
1. Plate probe: after the steel plate used to make large-caliber submerged arc welding straight seam steel pipe enters the production line, the ultrasonic inspection of the whole plate shall be carried out first.
2. Edge milling: double-sided milling is carried out on the two edges of the steel plate through the edge milling machine, so as to achieve the required plate width, plate edge parallelism and groove shape.
3. Pre-bending edge: use the pre-bending machine to pre-bend the edge of the plate, so that the edge of the plate has the required curvature.
4. Forming: on the JCO molding machine, first of all, one half of the pre-bent steel plate is pressed into the "J" shape after several step stamping, and then the other half of the steel plate is also bent into the "C" shape, and finally forms the "O" shape of the opening.
5. Pre-welding: the straight welded steel pipe after forming is welded together and continuously welded by gas shielded welding (MAG).
6. Internal welding: longitudinal multi-wire submerged arc welding (up to four wires) is adopted to weld the inner side of straight seam steel pipe.
7. External welding: longitudinal multi-wire submerged arc welding is adopted to weld the outer side of straight seam submerged arc welding pipe.
8. Ultrasonic inspection Ⅰ: inside and outside of straight seam welded steel pipe weld and weld on both sides of the base of 100% of the check.
9. X-ray Ⅰ: 100% of inside and outside weld X-ray industrial TV inspection, using image processing system to ensure the sensitivity of detection.
10. Diameter enlargement: the full length of the straight seam pipe of submerged arc welding is enlarged to improve the dimensional accuracy of the pipe and the distribution of internal stress of the pipe.
11. Hydraulic test: the pipe after diameter enlargement is tested one by one on the hydraulic test machine to ensure that the pipe meets the standard test pressure. The machine has the function of automatic recording and storage.
12. Chamfering: machining the pipe end of the pipe after passing the inspection to reach the required pipe end groove size.
13. The ultrasonic inspection Ⅱ: root by ultrasonic inspection to check again after the straight seam welded steel pipe in the hole diameter, water pressure may produce defects.
14. X-ray Ⅱ: for hole enlargement and after water pressure test of tube X-ray industrial TV inspection and pipe weld filmmaking.
15. Magnetic particle inspection of pipe end: conduct this inspection to find defects of pipe end.
16. Anticorrosion and coating: qualified steel pipe shall be anticorrosion and coating according to user requirements.
Carbon steel straight seam pipe applications
1. Generally, welded pipes are used for conveying water, gas, air, oil, heating steam and other generally low-pressure fluids.
2. Common carbon steel wire bushing (gb3640-88) is a steel pipe used to protect electric wires in industrial and civil buildings, installation machinery and equipment and other electrical installation projects.
3. Straight seam electric welding pipe is a pipe with longitudinal parallel welding seam and steel pipe. Generally divided into metric welding pipe, welding thin wall pipe, transformer cooling pipe and so on.
The difference between straight Carbon steel seam pipe and seamless Carbon steel pipe
1. Different processing technology: seamless pipe is made of high quality carbon steel or alloy steel. Seamless pipe processing technology is divided into cold drawing and hot rolling two ways, and slit pipe is generally welded.
2. Different USES: seamless pipe is mainly used for conveying fluid pipes or structural parts, mainly used in the mechanical industry, and slit pipe is mainly used in the construction industry, such as water, gas, compressed air and other low-pressure fluid. But the pressure pipes involved are all seamless steel tubes.
3. Different prices: because the production process of seamless steel tube is more complex, the price is relatively expensive compared with the welded steel tube, and the welded steel tube is mainly made of steel plate (steel belt) through secondary welding, which is cheap and widely used.
