Q235B Longitudinal High-frequency Welded Steel Pipe

Q235B Longitudinal High-Frequency Welded Steel Pipe Product Introduction

Q235B longitudinal high-frequency welded steel pipe refers to steel pipe made of Q235B steel, welded longitudinally using high-frequency induction welding (HFI) or resistance welding (ERW) processes. This type of steel pipe is known for its relatively simple process and fast production speed, and is widely used in low-pressure fluid transportation (water, gas, air), general engineering, and light industrial products.

Manufacturing Process

1. Uncoiling and Leveling: Q235B hot-rolled coils are uncoiled and leveled to eliminate curling stress.

2. Edge Milling: The edges of the strip are precision machined using a double-blade milling machine to ensure a smooth weld surface.

3. Forming and Welding: The strip is formed into a tubular shape through multiple roll bending processes and instantaneous fusion is achieved using high-frequency induction welding (100-400kHz).

4. In-line Heat Treatment: The weld is subjected to medium-frequency induction annealing to eliminate residual weld stress.

5. Sizing and Straightening: A hydraulic straightener is used to ensure straightness deviation ≤1mm/m.

6. Hydrostatic Test: The standard requires holding at a pressure of 6MPa for ≥5 seconds.

Compared to spiral welded pipes, straight seam welded pipes offer higher dimensional accuracy (diameter tolerance ±0.5mm) and lower ovality (≤0.6%D), making them particularly suitable for applications requiring precision assembly. The report shows that advanced production lines using JCOE forming technology can achieve wall thickness uniformity within ±5%.

Current Market Situation and Price Trends for Q235B Welded Pipes

Latest price quotes show that the raw material cost for Q235B welded pipes has decreased compared to before.

About our company

GNEE STEEL boasts years of export experience and collaborates with numerous top-tier steel mills in China, enabling us to provide high-quality steel products at competitive prices. We also offer material certificates and other quality inspection documents, as well as export documents such as ocean freight declarations. Partnering with us guarantees your peace of mind. 

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