The production of hot-rolled seamless steel pipes involves rolling solid ingots into hollow tubes without seams. This process is applicable to carbon steel, alloy tubes, high alloy steel, and some non-ferrous metals. The resulting seamless steel pipes have an outer diameter range of 16 to 1600 mm and a wall thickness of 2 to 200 mm.
Types of Tubes Produced
Round-section tubes
Special-section tubes
Variable-section tubes
Hot-rolled seamless steel pipes can be used directly or as raw materials for cold drawing and cold-rolled tubes. Approximately 80% to 90% of seamless steel pipes are produced using the hot-rolling method.
Tube Billets for Hot-Rolled Steel Pipes
Ingots
Continuous casting billets
Rolled billets
Forged billets
Hollow casting billets
Basic Production Process
- Piercing
The ingot or billet is pierced into a hollow thick-walled rough tube using a piercing machine.
Piercing methods include two-roller oblique rolling, pressure perforation, push rolling, and three-roller oblique rolling.
- Stretching
The rough tube is rolled thin and stretched to a wall thickness close to that of the finished tube.
Stretching methods include rolling on an automatic tube rolling mill, continuous tube rolling mill, three-roll and two-roll tube rolling mills, periodic tube rolling mills, and jacking machines.
- Finishing
The rough tube undergoes finishing rolling to become a finished tube.
Finishing processes include tube leveling and sizing to improve quality, as well as diameter reduction and hot expansion to meet specific product specifications.
Production Units
The units for producing hot-rolled seamless steel tubes are named based on the equipment used in the piercing, stretching, and finishing processes. Examples include:
Automatic Pipe Rolling Mill Unit: Uses an automatic pipe rolling mill for stretching.
Continuous Pipe Rolling Mill Unit: Uses a continuous pipe rolling mill.
Three-Roll (or Two-Roll) Pipe Rolling Mill Unit: Uses three-roll or two-roll inclined rolling mills.
Periodic Pipe Rolling Mill Unit: Uses a periodic pipe rolling mill.
CPE Pipe Jacking Unit: Uses a CPE pipe jacking machine.
These units are integral to the production of high-quality seamless steel pipes, ensuring consistency and precision in the final product.
United Steel Industry As the most important steel pipe manufacturer and exporter in China, in the past 20 years, we have completed more than 100 projects, with partners in more than 100 countries, and established relationships with oil and gas and EPC companies in many countries business relationship.
For more information about the product price, catalog and rolling mill inspection certificate,
please consult:Email:Sales@usisteels.com
