High-frequency straight seam electric-resistance welded (ERW) steel pipe is a type of welded steel pipe manufactured using advanced high-frequency welding technology. This process involves the use of hot-rolled steel coils, which are transformed into pipes through a series of precise forming and welding steps. The unique welding method, which leverages the skin effect and proximity effect of high-frequency currents, ensures a strong and seamless bond between the edges of the steel strip. Here we will introduce you the manufacturing process of ERW pipes.

Material Preparation:

The process begins with hot-rolled steel coils, which are uncoiled and leveled to ensure uniformity. These coils are typically made from low-carbon or mild steel, providing a good balance of strength and flexibility.

Forming:

The steel strip is passed through a series of forming rolls in a continuous process. These rolls gradually shape the flat strip into a cylindrical form, bringing the edges of the strip together in preparation for welding.

High-Frequency Welding:

The edges of the steel strip are heated using high-frequency electrical currents. The skin effect ensures that the current flows primarily on the surface of the steel, while the proximity effect concentrates the current at the edges where the two sides of the strip meet. This localized heating melts the edges, and pressure is applied by squeeze rolls to fuse them together, creating a seamless weld.

Cooling and Sizing:

After welding, the pipe is cooled and passed through sizing rolls to achieve the desired diameter, wall thickness, and roundness. This step ensures high dimensional accuracy and a smooth surface finish.

Cutting and Inspection:

The pipe is cut to the required length and undergoes rigorous quality control checks, including non-destructive testing (NDT) methods like ultrasonic testing or eddy current testing, to ensure the integrity of the weld and overall quality.

In conclusion, high-frequency straight seam electric-resistance welded (ERW) steel pipes are a versatile and reliable solution for a wide range of industrial applications. Their unique manufacturing process, superior weld quality, and cost-effectiveness make them a preferred choice for industries such as oil and gas, water supply, construction, and automotive.