Jiangsu Shunli Steel Group has 3 large-scale spiral submerged arc welded pipe production lines, which can produce steel pipes with diameters of Φ219～Φ3200, with an annual production capacity of 200,000 tons. Next, we will learn more about the company's super-long pipe piles through the introduction of the on-site production process and operation points of large diameter and unequal thickness super-long pipe piles!
Here is the content list:
What are the characteristics and construction difficulties of super-long pipe pile?
What is the production process of super-long pipe pile?
About on-site butt welding of super-long pipe pile.
Jiangsu Shunli Steel Group uses reasonable manufacturing equipment to assemble, weld and paint super-long pipe piles on site, effectively controlling the size deviation and welding deformation of super-long pipe piles. All production lines are equipped with online ultrasonic flaw detection equipment, and there are manual ultrasonic flaw detection, magnetic particle flaw detection, radiographic flaw detection and other inspection methods for customers to choose. The steel pipe pile support produced is mainly used for pile foundation engineering, bridge construction and steel structure engineering.
The super-long pipe pile is characterized by the largest pile length, with a maximum weight of 80 tons. The appearance quality requirements are high, the outer circumference of the pipe is ±10 mm, the pipe end ellipticity is ±5 mm, the pipe end flatness is 2 mm, the pipe end plane tilt is not more than 4 mm, and the pile axis bending height is L/1000 and not more than 30 mm, The butt joints of the pipe joints shall not be greater than 2 mm; the quality of the welds shall be Class I.
Super-long pipe pile assembly due to the super-long steel pipe pile and heavy tonnage, the assembly of the entire pile requires high dimensional accuracy, so it is constructed in sections and the entire pile assembly scheme. The quality control of segmented production will directly determine the assembly quality and weld quality of the super-long pipe pile after assembly, and it is one of the key factors for the overall assembly welding quality of the steel pipe pile.
The assembly welding seam is a circular closed form, with a large welding filling volume, small internal space, poor working environment, and high welding seam quality requirements. In order to effectively ensure the welding quality of super-long pipe pile, scientific and rigorous welding procedures and safety measures must be formulated.
The shrinkage deformation of super-long pipe pile is the basic unit of welding deformation. The cooling process of the weld is the process in which the weld metal is transformed from liquid to solid. The transformation process will produce welding stress and shrinkage of the weld, which will lead to welding. The external dimensions of the rear welded parts change, which affects the quality. In order to ensure that the quality of the project can meet the design requirements, the entire welding process of the super-long pipe pile must be closely and effectively monitored.
In the production of super-long pipe pile, a single super-long pipe pile is divided into multiple parts for manufacturing, and then assembled into a whole. It is planned to build a steel pipe pile processing plant near the coast and rent a small-tonnage wharf for assembly. The length of the super-long pipe pile joint is limited to 12m. The construction is divided into preparation, steel pipe pile production, steel pipe pile painting and dock pile group supporting.
The relevant technical indicators of the raw materials directly affect the quality of the super-long pipe pile. Select steel plates, fluxes, welding rods, anti-corrosion coatings and other materials according to the requirements of the drawings. The grade specifications and appearance quality must conform to the design!
For the super-long pipe pile that meets the inspection requirements, please cut the material according to the design drawings. According to the feed, the length of a single pipe section is controlled within 3 meters. Φ1500mm steel pipe pile: δ=22mm slab size is 3000×4641 mm; δ=24 mm flat plate size is 3000×4635 mm; Φ1000mm steel pipe pile: δ=20mm slab size is 3000×3076 mm.
First, introduce the welding sequence and method of super-long pipe pile: first on the outside, then on the inside, all are welded by manual arc welding. There are 2 electric welding machines symmetrically welding the outside of each circumferential seam. First complete the welding of 3/4 of the outer circumferential seam, then use a 5 ton hoist to roll and place the entire pile, and then continue to complete the remaining 1/4 of the outer circumferential seam.
Then, the description of the inner circumferential seam welding of the super-long pipe pile: first use carbon arc gouging to complete the inner circumferential seam 1/2 root removal, polish with a grinding wheel grinder, weld 1 to 2 times with a Φ5mm electrode, and then use 5 tons Roll up and position the entire hoist, and continue to remove the roots and weld the remaining part of the inner circumferential seam.
The last thing to note is that the welding rod of super-long pipe pile must be baked at 350~380℃ for 1 hour before use. After drying, it should be slowly cooled and stored in an incubator at 100°C for later use. During use, put them in the thermal insulation tube that you carry with you; if it is strong wind, please stop running when the humidity is high and it is raining.
In the process of making super-long pipe pile, Jiangsu Shunli Iron and Steel Group strictly follows the requirements of drawings, standards and specifications, timely checks the quality of welds, strictly implements the "three inspections" system, and effectively controls the quality!