Precision rolled pipe is a higher-grade seamless steel pipe product with the characteristics of high precision and high surface finish requirements. In particular, the quality requirements of seamless steel pipes for oil cylinders are higher than other varieties. Most manufacturers adopt the production technology of two-roller cold rolling mill and three-roller cold rolling mill. Based on the existing equipment conditions, the steel pipe factory provides finished rolled pipe blanks through cold drawing method and finds out a more reasonable production process. As a precision-rolled tube blank, this product can produce high-quality seamless steel tubes for gas cylinders.
Characteristics of finishing - rolled tube editor
1. Cold-rolled precision steel pipes have high tolerance and dimensional accuracy, product accuracy is controlled at +/-0.05mm, the inner and outer walls have good finish, and there is no oxide layer on the surface.
2. Cold-rolled precision steel pipes have excellent comprehensive properties and can withstand high pressure, cold bending, flaring, and flattening without cracking or wrinkling, and can be subjected to various complex deformations and mechanical processing.
3. The promotion and application of precision seamless pipes can save steel, improve processing efficiency, reduce investment in processing procedures and equipment, save costs and greatly save processing hours, increase production capacity and material utilization, improve product quality and reduce costs.
Cold-rolled precision steel pipes are widely used in automobiles, motorcycles, electric vehicles, petrochemicals, electric power, ships, aerospace, bearings, pneumatic components, medium and low-pressure boilers and other fields.
Process requirements:
In order to ensure that qualified tube blanks are provided for cold rolling and meet the requirements of finish rolling tube blanks, the original cold drawing process has been improved:
1. Drill oblique holes in the ITD after upsetting to create conditions for pickling and cleaning the inner surface of the steel pipe;
2. Carry out multiple fine washings after pickling to ensure the inner surface of the steel pipe is clean and create conditions for phosphating.
Reduce defects such as internal scratches caused by cold drawing;
3. Use multiple passes of short mandrel drawing and one taper inner mold before finished product to increase the deformation of the inner surface of the steel pipe.
4. Change the heat treatment system. The intermediate heat treatment of semi-finished products adopts complete annealing, and the heat treatment of finished products adopts recrystallization annealing.
