The manufacturing process involves cold drawing or cold rolling followed by precisely controlled heating and natural air cooling. This simplified heat treatment methodology requires no specialized rapid cooling equipment, making it both efficient and cost-effective while delivering consistent material properties. The resulting normalized condition provides optimal balance between strength and processability for general engineering applications.

These NBK condition pipes develop fine-grained pearlitic (or pearlitic-ferritic) microstructure through the normalizing process, completely free from martensitic brittle phases that occur after quenching. The homogeneous material structure exhibits significantly reduced internal stresses compared to non-heat-treated tubes, ensuring enhanced dimensional stability and reliable performance in various operating conditions.

The balanced mechanical properties of Normalized Steel Pipes demonstrate higher strength and hardness than annealed tubes (GBK condition) while maintaining better plasticity and toughness than non-heat-treated hard condition tubes (BK). Typical Q235 material normalized pipes achieve tensile strength of 400-550MPa with elongation ≥21%, providing excellent all-around performance for general mechanical applications.

These normalized steel tubes offer good processability for immediate machining, welding, and bending operations without requiring additional stress relief annealing. The simplified manufacturing process reduces production cycles and costs while maintaining straightness and roundness accuracy suitable for conventional mechanical assembly requirements.

Technical Advantages:

  • Refined grain structure through normalized heat treatment

  • Balanced mechanical properties between strength and toughness

  • Reduced internal stresses for improved dimensional stability

  • Immediate processability without additional heat treatment

  • Cost-effective manufacturing with simplified processing

  • Consistent performance for general engineering applications

Normalized Steel Pipes serve effectively in mechanical manufacturing for gear blanks, shaft sleeves, and support brackets where balanced performance and machining efficiency are prioritized. These normalized condition tubes are widely used in medium-low pressure fluid transportation systems including water supply, drainage, and compressed air pipelines, as well as general service piping in chemical and power industries.

The automotive and agricultural machinery sectors utilize these pipes for chassis supports and transmission shafts where standardized processing requirements dominate. General mechanical applications include pump housings, fan casings, and impeller components that benefit from the consistent mechanical properties and reliable processability of normalized tubes.

Supported by Tenjan's 21 years of seamless tube specialization and 30 years of technical expertise in our R&D team, we provide customized normalized solutions tailored to your specific application requirements. Our advanced manufacturing capabilities ensure each Normalized Steel Pipe (NBK/+N Condition) meets exact specifications for materials, dimensions, surface quality, and mechanical properties, delivering reliable performance for your engineering applications.