(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 degree of the end of the steel pipe during cutting, the cutting edge generally adopts a shaped blade. For seamless steel pipes that are prone to shear cracks, the steel pipes are preheated to 300°C during shearing.
(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 devices include bow 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.
How to cut large-diameter carbon steel seamless pipe?
Large-diameter carbon steel seamless pipes refer to large-diameter seamless steel pipes with an outer diameter of 1000mm or more. Large-diameter seamless steel pipes are made of steel ingots or solid tube blanks that are perforated into capillary tubes, and then hot-rolled, cold-rolled or cold-drawn. The large-diameter seamless steel pipes we purchased may be long or short. If they are short, they can be welded. If they are long, the excess parts must be removed, that is, cut off, so that their length is suitable for the length required for construction.
There are many ways to cut large-diameter seamless pipes. The following three common cutting methods for large-diameter seamless pipes are introduced.
1. Use a sawing machine. The characteristic of the sawing machine is that the cut is neat and convenient for welding during construction. The disadvantage is that the efficiency is too low, that is, too slow.
2. Use artificial gas cutting. The characteristic is that it is fast, but the disadvantage is that the surface of the cut is jagged, which hinders the construction.
3. Use the pipe self-propelled automatic cutting machine. The characteristics of using the self-propelled automatic pipe cutting machine are low cost, and the cut is smooth and neat. After cutting with the self-propelled automatic pipe cutting machine, there is not much difference between the large-diameter cold-drawn seamless steel pipe and the cut with a sawing machine.
Precautions for carbon steel pipe cutting:
