The seamless steel tube is bent because the rolling mill is not properly adjusted, the residual stress remaining during rolling, and the unequal cooling due to the cross-section and length of the tube. Therefore, it is impossible to obtain a straight steel pipe directly from the rolling mill, as long as the tortuosity of the cold straightening steel pipe is sufficient to satisfy the rules of the skill condition.
The straightforward principle is to make the seamless tube elastically and plastically bend, and the large bending degree becomes a small degree of curvature, so that the steel pipe needs to be repeatedly bent in the straightening machine. The degree of repeated bending of the steel pipe is mainly determined by the adjustment of the steel pipe straightening machine. There are many factors that affect the quality of straightening, such as the bending of the original pipe, the size of the steel pipe and the type of material straightening machine, and the adjustment parameters.
Cold drawn seamless steel pipe production method:
1. no core rod drawing (only need to add a mandrel when pulling out the pipe);
2. short mandrel drawing (pulling die and axial fixed when drawing Short core rod with small length);
3. Long core rod drawing (the drawing method is used when drawing and the long core with the length of the tube moving slightly along with the drawn steel tubeRod);
4. the moving mandrel is drawn (the pulling mandrel and the short mandrel which can be stably maintained in the deformation zone without axial fixation).
In the meantime, the first two are widely used in production; the coreless drawing is used to reduce the outer diameter of the steel pipe; the other three kinds of cored rods are mainly used to tighten the wall thickness of the steel pipe, and also have a certain diameter reduction. Deformation.
Cold drawn shaped steel pipe has a variety of shape specifications. By designing different shapes of molds, cold drawing out different cross-sectional shapes, different size specifications and tolerances. The angle can be set to a right angle or a rounded corner. Using high-quality carbide molds and professional technicians, the tolerances are accurate and uniform. The surface is smooth. The advanced cold drawing process makes the surface of cold drawn steel products smooth and bright. Significant material savings. Cold drawn steel is the shape and the required specifications and tolerances for cold extrusion of raw materials. The loss of raw materials is very small. Compared with the materials lost by traditional lathe machining, the material saved by cold drawn steel is very Appreciably, especially when the amount of materials is large, the material cost is more significant. Due to the cold drawn triangular steel pipe, the cold drawn steel bar has high precision, reduces the generation of waste, shortens the processing time and reduces the production cost. Cold drawn or cold drawn triangular steel pipe and triangular steel bar products are widely used in machinery manufacturing, light industry, hardware, standard parts, bicycles, automobiles, motorcycles, textile machinery, transformers and other machinery industries.
Shaped seamless pipe, profiled seamless steel pipe, profiled steel pipe, profiled welded pipe, cold drawn steel pipe surface is in good condition, cold drawn steel products can be used directly, such as spraying, sanding, bending, drilling can also be refined according to actual requirements Direct plating eliminates the need for processing.
Cold drawn precision seamless steel pipe, cold drawn round pipe cold drawn seamless pipe and special-shaped steel pipe, non-standard shaped steel pipe, etc. can be customized according to customer requirements, materials are 10#, 20#|35#, 45#, 20cr, 40cr, 20crmo 40Crmo, seamed and seamless shaped tubes. The dimensions of these steel pipes cover from 1" to 24". They can be produced according to Chinese GB, Japanese JIS, German DIN, American ASTM and other standards.