Hot-expanded seamless steel pipe

What is hot-expanded seamless steel pipe?

Hot-expanded seamless steel pipe is what we often call hot-expanded pipe. Steel pipes with relatively low density but strong shrinkage (seamless steel pipes) can be referred to as hot-expanded pipes. A rough pipe finishing process that uses oblique rolling or drawing to expand the diameter of the pipe. It is a development trend in the international pipe rolling field to thicken the steel pipe in a shorter period of time, produce non-standard and special types of seamless pipes, and have low cost and high production efficiency.

The hot expansion process involves heating the preformed seamless pipe and then expanding it hydraulically or mechanically to increase the diameter of the pipe. This allows precise control of the size and ensures uniformity throughout the pipe. The result is a high-quality pipe that can withstand harsh environments, which is very suitable for industries such as petrochemicals, construction and infrastructure projects.

What is the technicality of hot-expanded seamless steel pipe forming

The specifications and models of hot-expanded seamless steel pipes are limited in hot-deformed steel pipe plants. Hot-deformed seamless steel pipes were developed according to customer needs. The specifications and specifications of hot-deformed straight seam steel pipes are arbitrary. They are usually manufactured according to customer requirements. Hot-deformed seamless steel pipes are a kind of hot-deformed seamless steel pipes with low relative density and strong collapse. Seamless pipes) can be called hot-deformed pipes. A seamless steel pipe used for hot expansion of pipe diameter according to cross-rolling or drawing expansion.

Hot-expanded seamless steel pipes are a combination of cone die expansion technology, large digital high-frequency electromagnetic induction heating technology, and hydraulic press technology. The technology is effective, energy consumption is low, infrastructure project investment is small, product quality is good, raw materials and product models are complete, production is flexible and changeable, and capital investment is small. Large adaptability replaces the traditional pulling and expanding technology in the seamless steel pipe manufacturing industry. Due to the recent inability to solve the supply of large-diameter steel pipes, hot-deformed seamless steel pipes have become an important commodity source to cope with the shortage of large-diameter steel pipes. Relieve the tense situation in the large-diameter steel pipe sales market

As an expansion of the main task of the smelter's pipe rolling, the "medium frequency induction heating, hydraulic press propulsion" pipe expansion process is adopted. The hot-expanded seamless steel pipe has received five-star praise in the industry for its complete specifications and models, high quality, convenient supply, high quality and low price.The thermal expansion seamless steel pipe adopts the expansion technology of the original pipe. The expansion is a pressure processing process that uses hydraulic or mechanical means to force the steel pipe to expand outward along the radial direction. The mechanical method is simpler and more efficient than the hydraulic method. The world’s most advanced large-diameter seamless steel pipe pipeline expansion process is adopted.

Production process of hot-expanded seamless steel pipe

The mechanical expansion diameter is expanded in the radial direction by the segmented fan-shaped block at the end of the expanding machine, so that the tube blank is stepwisely formed in a stepwise manner to realize the process of plastic deformation of the entire pipe length, thereby producing a thermally expanded seamless steel pipe. It is divided into 5 phases:
1. Initial rounding stage: The fan-shaped block is opened until all the fan-shaped blocks are in contact with the inner wall of the steel pipe. At this time, the radius of each point in the inner pipe of the steel pipe is almost the same in the step length, and the steel pipe is initially rounded.
2. Nominal inner diameter stage: The fan block reduces the speed of movement from the front position until it reaches the required position, which is the inner circumference position of the finished product of the quality requirement.
3. Rehabilitation compensation phase: The fan-shaped block starts to move at a lower speed in the 2-stage position until it reaches the required position, which is the inner circumferential position of the steel pipe before the rebound of the process design.
4. Pressure-stabilizing stage: The fan-shaped block remains in the inner circumferential position of the steel pipe for a period of time before the rebound, which is the pressure-stabilizing stage required by the equipment and the expansion process.
5. Unloading return phase: The fan-shaped block is rapidly retracted from the inner circumferential position of the steel pipe before the rebound, until reaching the position of the initial expansion, which is the minimum shrinkage diameter of the segment required by the expansion process.

In practical applications, in the process simplification, the steps 2 and 3 can be combined and simplified, which has no effect on the diameter of the steel pipe.Benefits of Hot Expanded Seamless Steel Pipe

Specifications of hot expanded seamless steel pipe

ITEM	OD(mm)	STD(6m)		SCH40(6m)		SCH80(6m)
		thickness	Wt/piece	thickness	Wt/piece	thickness	Wt/piece
		(mm)	(kg)	(mm)	(kg)	(mm)	(kg)
14〞	355.6	9.53	487.98	11.13	567.30	19.05	948.61
16〞	406.4	9.53	559.62	12.70	739.80	21.44	1221.19
18〞	457.0	9.53	630.96	14.27	934.80	23.83	1527.3
20〞	508.0	9.53	702.90	15.09	1100.52	26.19	1867.05
24〞	610.0	9.53	846.72	17.48	1532.46	30.96	2652.49

Appearance: 5.8 M/6M/12M, SRL, DRL, grooves above 2 inches, bundled, painted black, wrapped with PE film
Standards: GB/T 8162-2008, GB/T 8163-2008, ASTM A106 Gr.B, ASTM A53 Gr.B, ASTM A210, ASTM A333, DIN1629, DIN2448, DIN17175, EN10216, EN10204, EN10297, EN10216, JIS3454, GOST 8734-75, GOST 8732-78
Steel grade: 10#, 20#, GR.B, X42-X60, P265TR1, Q345B, S355JRH etc
External coating anticorrosion: 3PE, FBE, cement mortar, etc.

Applications of Hot Expanded Seamless Steel Pipe

Hot expanded seamless steel pipes are used in a variety of industries, owing to their strength, durability, and resistance to extreme conditions. Here are some of the most common applications:
Oil and Gas Industry: These pipes are essential in the oil and gas sector, where they are used for transporting oil, natural gas, and other fluids under high pressure. The corrosion-resistant properties make them ideal for offshore and subsea applications.
Construction and Infrastructure: Hot expanded seamless pipes are used in structural applications, including bridges, highways, and buildings, where their strength and precision are required.
Automotive Industry: In the automotive sector, hot expanded seamless steel pipes are used in the manufacturing of various vehicle components, such as exhaust systems and structural parts.
Power Generation: These pipes are also used in power plants, particularly in the production of steam turbines, heat exchangers, and other high-temperature systems.

Chemical and Petrochemical Industries: The pipes' resistance to corrosion makes them ideal for transporting chemicals, particularly in environments where other pipes may degrade.

Conclusion

Hot expanded seamless steel pipes are a high-performance solution for various industries, offering superior strength, durability, and resistance to extreme conditions. From the oil and gas industry to construction and power generation, these pipes are an essential component in many applications. By understanding the manufacturing process, benefits, and applications of hot expanded seamless steel pipes, you can make an informed decision when selecting the right pipes for your project.
For businesses looking to source hot expanded seamless steel pipes, it’s important to choose a reliable supplier that adheres to industry standards and offers competitive pricing. This will ensure that you receive high-quality pipes that meet your specific needs while maximizing your investment.