In-depth understanding of the production process of ERW steel pipe

Learn more about the production process of ERW steel pipes - efficient manufacturing from raw materials to finished products

With the rapid development of global infrastructure construction, energy development and machinery manufacturing, ERW (Electric Resistance Welded) steel pipes, as an important category of structural pipes, transportation pipes and engineering pipes, have attracted more and more attention from industry customers for their high-efficiency and high-precision manufacturing processes. Relying on advanced equipment and strict process control, BAOWI Steel has built a high-quality and high-capacity ERW steel pipe production line to meet the diversified needs of construction, oil, natural gas, water conservancy, electricity and automobiles.

What is ERW steel pipe?

ERW steel pipe is a straight seam welded pipe made by using high-frequency current to instantly heat the edge of the steel strip and pressurize it. Compared with traditional spiral welded pipes or seamless steel pipes, ERW pipes have many advantages such as fast forming, short welds, high strength, good wall thickness consistency, and smooth appearance. They are especially suitable for large-scale, standardized industrial pipe production.

Raw material preparation: high-quality steel strip is the key
The starting point of ERW steel pipe manufacturing is the selection of steel strips. BAOWI strictly selects hot-rolled or cold-rolled low-carbon structural steel and low-alloy steel (such as Q195, Q235, Q345, X42~X70, etc.), and through uncoiling, leveling, shearing and surface treatment processes, ensures that the steel strip has good plasticity, cleanliness and thickness uniformity, laying a solid foundation for subsequent welding and forming.

Forming process: precision roll forming, stable control of pipe diameter
The pre-treated steel strip is fed into the forming unit, and gradually curled from a flat surface into a circular or rectangular closed tube under the action of multiple precision rollers. During the entire rolling process, it is crucial to control the consistency of the pipe diameter, the edge butt accuracy and the stability of the curling line. BAOWI uses a fully automatic roll group replacement system and CNC forming technology to quickly adjust different specifications of pipes and improve production flexibility and stability.

High-frequency welding: core technology ensures weld quality
The welding of ERW steel pipes adopts high-frequency resistance welding (usually high-frequency induction welding), which uses the eddy current effect to quickly heat the edge of the steel strip to the melting point, and completes the butt welding under the pressure of the extrusion roller. Compared with traditional fusion welding, high-frequency welding has a small heat-affected zone, uniform weld inside and outside, and superior mechanical properties. It is an ideal choice for high-strength structural pipes.

BAOWI steel uses internationally advanced solid-state high-frequency welding equipment and introduces an automatic monitoring system to detect welding temperature, current intensity and weld state in real time to ensure welding consistency and reliability. The weld nodules are removed by automatic milling equipment inside the weld and the outside is smoothed to achieve an almost seamless visual effect.

Heat treatment and shaping: improving the comprehensive performance of steel pipes
After welding, the steel pipe enters the heat treatment section for weld annealing (optional) to eliminate welding stress and restore the material's organizational structure so that the weld area is consistent with the mechanical properties of the parent material. Subsequently, the steel pipe is sized and rounded or squared by shaping rollers in the sizing unit to ensure that the product meets the standard dimensional tolerance and meets the subsequent installation and matching requirements.

Ultrasonic and eddy current testing: full-process online quality control
Quality control in the production process of ERW steel pipes is crucial. BAOWI has introduced an automated online non-destructive testing system, including ultrasonic testing, eddy current testing, and laser diameter measurement equipment, to monitor and alarm key indicators such as welds, wall thickness, outer diameter, and ovality in real time, ensuring that each steel pipe leaving the factory meets international standards or customer-specified standards (such as API 5L, ASTM A53, EN 10219, etc.).

Anti-corrosion and packaging treatment: ensuring transportation and later use
After the finished steel pipe is offline, the inner and outer walls can be treated with anti-corrosion according to customer needs, including black paint coating, hot-dip galvanizing, epoxy spraying, plastic layer coating, etc., to effectively prevent corrosion problems in humid, acidic, alkaline, salt spray and other environments. At the same time, standardized packaging processes such as steel strapping, port protection, and pipe cap sealing are used to ensure safety and cleanliness during long-distance transportation.

Diversified product application scenarios
At present, the ERW steel pipes produced by BAOWI are widely used in:

Municipal water supply and drainage, natural gas transmission, oil and gas pipelines and other pressure transmission systems;

Structural pipes such as building steel structures, plant trusses, columns, curtain wall keels, etc.;

Industrial manufacturing fields such as agricultural machinery and equipment, automobile manufacturing, and home appliance brackets;

Construction of public facilities such as power towers, bridge guardrails, and highway anti-collision systems.

Looking to the future: Technology upgrade and green manufacturing in parallel
BAOWI Steel said that the company will continue to invest in the construction of automation and intelligent manufacturing systems, improve production efficiency and yield rate through industrial Internet and big data analysis, and promote energy-saving and emission reduction process transformation, introduce high-efficiency energy-saving welding power supplies and waste heat recovery systems, and move towards green manufacturing and sustainable development.

About BAOWI Steel Company

BAOWI Steel is a modern steel pipe manufacturing company integrating R&D, production, processing and export. Its main products cover ERW steel pipes, spiral welded pipes, seamless steel pipes, rectangular pipes, square pipes and other series. The company's products widely serve the core areas of the national economy, such as energy, construction, transportation, manufacturing, and agriculture, and have won wide recognition from global customers with their excellent quality and quick response.