Seamless steel pipe process performance testing method

Seamless steel pipes are categorized into hot-rolled (extruded) and cold-drawn (rolled) based on their manufacturing processes. Cold-drawn (rolled) tubes further divide into round tubes and special-shaped tubes. The process performance of seamless pipes can be assessed through several tests: hydraulic (water) pressure, flattening, bending, and flaring tests. These evaluations ensure the steel pipe's quality and suitability for subsequent processing and manufacturing. Here are some insights from carbon steel tube manufacturers on these critical tests.

Hydraulic (Water) Pressure Test

In this non-destructive test, water at a specific pressure is poured into the steel pipe, and the pressure is maintained for a predetermined period (based on standard values). The pipe must not leak during this time, ensuring the pipe's integrity under pressure.

Flattening Test

The steel pipe sample is placed between two flat clamps, and force is applied until the distance between the clamps reaches the standard value. The sample is then inspected for cracks, fractures, or other defects in the deformed area, ensuring the pipe's durability when flattened.

Bending Test

The steel pipe sample is placed on a bending testing machine and bent to the angle required by the standard, following the bending core radius specified. The surface at the bending position should show no defects, such as cracks or tears, confirming the pipe's flexibility and strength.

Expansion Test

The steel pipe sample is positioned on a work surface with the opening upward. A top center, chosen according to the standard's specified taper, is pressed into the pipe until the outer diameter expansion rate meets the standard. The sample's surface should remain free of defects like cracks, ensuring the pipe's ability to withstand expansion.

These tests are crucial for verifying the process performance and ensuring the high quality of seamless steel pipes.