Cold Rolled Seamless Steel Pipe

Cold Rolled Seamless Steel Pipe refers to a premium seamless tubular product manufactured by cold rolling processes at temperatures below the metal’s recrystallization point(typically room temperature),using hot-rolled seamless tube blanks as raw materials.Unlike welded pipes,it has no longitudinal or circumferential welds;its monolithic structure ensures exceptional structural integrity,pressure resistance,and reliability.It is widely specified in high-precision,high-pressure,and corrosion-sensitive industrial applications.

Manufacturing Process

Raw Material Preparation:Select high-quality hot-rolled seamless tubes,conduct chemical composition and mechanical property inspections,followed by pickling and derusting to remove surface oxides.

Cold Rolling Forming:Process in two-high or multi-high Pilger mills,with the tube passing through annular grooves and fixed mandrels for continuous reduction in wall thickness and precise diameter control.

Heat Treatment:Intermediate annealing to eliminate work hardening;final annealing/tempering to achieve the required mechanical properties(such as soft,half-hard,or hard delivery states).

Finishing&Quality Control:Straightening,degreasing,cutting,and rigorous non-destructive testing(ultrasonic testing,eddy current testing),hydrostatic pressure testing,and dimensional/surface inspection before packaging.

Key Features&Advantages

Ultra-High Dimensional Precision:OD tolerance can be controlled within±0.05mm,wall thickness deviation≤±5%,minimal ovality,meeting the assembly requirements of precision mechanical parts.

Superior Surface Finish:Surface roughness Ra=0.4–0.8μm,bright and oxide-free,reducing fluid friction resistance,minimizing machining allowances,and improving coating adhesion.

Enhanced Mechanical Properties:Cold work hardening refines grains,increasing tensile strength by 30–50%compared to hot-rolled pipes,with higher surface hardness and excellent fatigue resistance.

Seamless Structure:No weld defects,enabling higher pressure-bearing capacity and better corrosion resistance in harsh environments.

Flexible Specifications:Can produce small diameters(down to 5mm)and thin walls(0.5mm and above)for specialized equipment.

Materials&Standards

Common Materials:Carbon steel(10#,20#),alloy steel(40Cr,12Cr1MoV),stainless steel(304,316L).

International Standards:ASTM A179/A192,EN 10305,JIS G3445,GB/T 3639(China precision seamless tube standard).

Typical Applications

Hydraulic&Pneumatic Systems:High-pressure oil pipes,cylinder barrels,precision tubing for construction machinery and machine tools.

Automotive&Aerospace:Fuel lines,brake pipes,instrument tubes,lightweight structural tubes.

Petrochemical&Power:Heat exchanger tubes,boiler tubes,instrumentation pipes in corrosive and high-temperature conditions.

Precision Instruments&Medical Equipment:Tubing for sensors,analytical instruments,and medical devices.

Packaging&Storage

Packed in bundles with steel straps,or in wooden boxes/crates for small-caliber precision pipes.

Labeled with standard,material grade,size,heat number,and batch number.

Stored in a dry,ventilated warehouse to prevent rust and mechanical damage.