Cutting method of seamless carbon steel pipe
There are many ways to cut seamless carbon steel pipes, such as oxyacetylene gas cutting, air plasma cutting, laser cutting, wire cutting, etc., can cut carbon steel. There are four common cutting methods:
(1) Flame cutting method: This cutting method has the lowest operating cost, but consumes more seamless pipe fluid and has poor cutting quality. Therefore, manual flame cutting is often used as an auxiliary cutting method. However, due to the improvement of flame cutting technology, some factories use multi-head flame cutting machine automatic cutting as the main method of cutting liquid carbon steel seamless pipe.
(2) Shearing method: This method has high production efficiency and low cutting cost. Medium carbon seamless pipes and low carbon alloy structural steel pipes are mainly cut by shearing. In order to improve the shearing efficiency, a large-tonnage shearing machine is used for double shearing; in order to reduce the flattening of the end of the steel pipe during cutting, the cutting edge generally adopts a special-shaped blade. For seamless steel pipes that are prone to shear cracks, preheat the steel pipe to 300°C during shearing.
(3) Fracture method: the equipment used is a fracture press. The breaking process is to use a cutting torch to cut all the holes at the predetermined breaking liquid pipe, then put it into a breaking press, and use a triangular ax to break it. The distance between the two points is 1-4 times the diameter Dp of the tube blank.
(4) Sawing method: This cutting method has the best cutting quality and is widely used in alloy steel pipes, high-pressure steel pipes, and fluid seamless pipes, especially for cutting large-diameter fluid seamless steel pipes and high-alloy steel pipes. Sawing equipment includes bows saws, band saws and circular saws. Cold circular saws with high-speed steel sector blades are used for cold sawing alloy steel pipes; cold circular saws with carbide blades are used for high-alloy steel saws.
Carbon steel pipe cutting precautions:
(1) Galvanized steel pipes and carbon steel pipes with a nominal diameter less than or equal to 50mm are generally suitable for cutting with a pipe cutter;
(2) High-pressure pipes and pipes with a tendency to harden should be cut by mechanical methods such as sawing machines and lathes. If oxyacetylene flame or ion cutting is used, the affected area of the cutting surface must be removed, and its thickness is generally not less than 0.5mm;
(3) Stainless steel pipes should be cut by mechanical or plasma methods;
Other steel pipes can be cut with oxyacetylene flame.