Features of finishing rolled tube editor
1. Cold-rolled precision steel pipes have high tolerance dimensional accuracy, the product accuracy can be controlled within +/-0.05mm, the internal and external walls are in good shape, 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, flared and flat shapes, without cracks or wrinkles, and can undergo 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, greatly save processing time, increase production capacity and material utilization, as well as improve product quality and reduce costs.
Organizing the purpose of scroll tube editing
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 for finishing rolled tube blanks, the original cold drawing process is improved:
1. Drill bit - inclined hole, behind its front line, in condition for pickling and cleaning the inner surface of the steel pipe;
2. After pickling, perform fine cleaning multiple times to ensure that the inner surface of the steel pipe is clean and produces clean conditions for phosphating.
Reduce defects such as internal scratches caused by cold painting;
3. Multi-pass short mandrel stretching and conical inner mold are used for the first time before the finished product to increase the deformation of the inner surface of the steel pipe.
Ensure uniform deformation of the inner and outer surfaces of the steel pipe;
4. Change the heat treatment system and use complete annealing for intermediate heat treatment of semi-finished products and recrystallization annealing for heat treatment of finished products.
Surface finish and mechanical properties of steel pipes after completion of rolling
The key points of the production process are as follows:
1. Pickling - H2SO4 concentration is 10% to 15%, temperature is 55-65°C, iron content is 100 g/L or less, pickling time is 30 minutes.
2. A variety of cleaning is required to clean the residue in the pipes;
3. The tapered outer mold and the cylindrical inner mold are used for the first few times of cold stretching, and the curved outer mold and tapered inner mold are used for the first time of the finished product.
All internal molds adopt "metal penetration internal mold"
4. Adopt full annealing heat treatment, the annealing temperature is 850-880°C, and the time is 15 minutes.
The finished product undergoes recrystallization annealing heat treatment to remove residual stress. The annealing temperature is 630-670°C and the time is 10 minutes;
5. Execute normal processes in other processes
