English
Seamless steel pipe is a weld-free steel pipe made by hot rolling or cold drawing process, with uniform cross-section and high strength. Compared with welded pipes, seamless steel pipes have higher strength, better pressure resistance and excellent corrosion resistance, making them suitable for applications that require higher performance.
Seamless steel pipes are widely used in industries such as oil, gas, chemicals, and electric power, mainly for conveying fluids, manufacturing mechanical parts, and structural support. Its excellent pressure resistance and corrosion resistance make it an ideal material for key industrial fields.
Seamless steel pipes are manufactured through a process that ensures a uniform structure without any welded seams. Here's a simplified overview of the main steps involved:
1.Billet Preparation: Select high-quality cylindrical steel billets and heat them to around 1200°C for malleability.
2.Piercing: Use a rotary piercing mill to create a hollow shell from the heated billet.
3.Rolling and Sizing: Roll and stretch the hollow shell through multiple rolling mills to achieve the desired diameter and wall thickness.
4.Heat Treatment: Enhance mechanical properties through annealing, quenching, or tempering.
5.Straightening and Cutting: Straighten the pipe to remove deformations and cut it to the required length.
6.Finishing: Perform surface treatments like shot blasting or polishing, and conduct non-destructive testing for quality assurance.
7.Inspection and Packaging: Inspect pipes for defects, mark them, and package for shipment.
Seamless pipe: Made from a solid cylindrical billet, heated and perforated to form a hollow tube. No welding is involved and there are no weld seams, making it stronger, more reliable and suitable for high pressure and temperature applications.
Welded pipe: Produced by rolling a steel plate or coil into a cylindrical shape and welding the edges together (e.g. using the ERW, SAW or EFW processes). There is a weld seam, which can be a potential weak point, although modern welding technology has significantly increased its strength.
High Strength and Pressure Resistance:
Seamless Steel Pipes: Due to the absence of welds, they have a uniform structure and higher strength, making them suitable for high-pressure, high-temperature, and highly corrosive environments. They are commonly used in oil and gas transportation, chemical equipment, boiler pipelines, and high-precision mechanical components.
Welded Steel Pipes: Although they have welds, modern welding technology has significantly improved their strength, making them suitable for medium- and low-pressure environments, such as building structures, water transportation pipelines, and HVAC systems.
Suitable Scenarios:
Seamless Steel Pipes: Primarily used in critical fields with high safety requirements, such as oil and gas exploration, high-pressure boilers, nuclear power plants, and aerospace equipment.
Welded Steel Pipes: Mostly used in general industrial fields, such as building frameworks, bridge supports, low-pressure fluid transportation, and general machinery manufacturing.
