Characteristics and Applications of Mild Steel Black Steel Pipe

What is Mild Steel Black Steel Pipe?

Mild Steel Black Steel Pipe is a specific type of steel pipe characterized by its low carbon content and black surface. It is typically uncoated or simply treated with rustproofing.

Core Definition:
Low Carbon: Refers to steel with a carbon content of 0.25% or less (such as ASTM A36, Q235B, etc.). It offers improved weldability and ductility, but lower hardness than high-carbon steel.
Black Steel: Its surface is dark gray or black, resulting from simple mill scale removal (such as sandblasting) after rolling, without any anti-corrosion treatment such as galvanizing or painting.

Features of Mild Steel Black Steel Pipe:

Mechanical Properties:
Tensile Strength: 400-550 MPa (lower than high-carbon steel, but with improved toughness).
Easy to cold bend and cut, suitable for on-site processing.

Surface Condition:
Natural mill scale (Fe₃O₄) after hot rolling. Anti-rust paint or asphalt coating is required before use.

Corrosion Resistance:
Bare pipes are prone to rust and require an external anti-corrosion coating (such as epoxy coal tar or 3PE coating).

Seamless Black Carbon Steel Pipe:

Seamless black steel pipes are produced by perforating solid steel billets into hollow cylindrical shapes. Since there are no welds, they are stronger and suitable for high-pressure applications.

Common Applications:

Low-pressure fluid transport: water, air, steam (non-corrosive media).
Structural support: building scaffolding, steel structure frames.
Mechanical manufacturing: equipment bases, hydraulic cylinders (requires subsequent finishing).

Selection Considerations:

1. Corrosion Protection Requirements:
For outdoor or humid environments, anti-rust paint or coating is required.

2. Pressure Limitation:
For low-pressure systems (typically ≤1.6 MPa), a wall thickness of SCH 80 or greater is required for high-pressure systems.

3. Welding Process:
Mild carbon steel is suitable for all welding methods (arc welding, gas shielded welding), but heat input must be controlled to prevent deformation.

Conclusion:
Mild carbon black steel pipe is an economical basic pipe material suitable for applications where corrosion resistance is not a high requirement and frequent processing is required. When using it, special attention should be paid to corrosion protection and pressure verification.

Read more:  China Seamless steel pipe manufacturer and supplier list or Mild Steel Seamless Pipe