There are several methods for cutting fluid seamless pipes, including shearing, breaking, sawing, flame cutting and anode cutting. Their characteristics are as follows:
(1) Flame cutting method-this cutting method has the lowest operating cost, but the fluid seamless pipe is worn out and the cutting quality is poor. Therefore, manual flame cutting is currently used as a supplementary cutting method. However, due to the improvement of flame cutting technology, some factories have used multi-head flame cutting machines to cut automatically as the main method of cutting fluid seamless pipes.
(2) Shearing method-This method has higher production efficiency and lower cutting cost. Low-carbon medium-carbon fluid seamless pipes and alloy structural steel pipes are mainly cut by shearing. In order to improve the shearing efficiency, a large-tonnage shearing machine is used to implement double-root cutting; in order to reduce the flatness of the end of the steel pipe during cutting, the general shear blade is a formed blade; for seamless steel pipes that are prone to shear cracks, shear Preheat the steel pipe to 300℃ when cutting.
(3) Breaking method-the equipment used is a breaking press. The breaking process is to cut a notch at the predetermined breaking fluid pipe with a torch, and then put it into the breaking press with a triangular axe blade to force it to break. The distance between the two supporting points is 4 to 5 times the diameter Dp of the tube blank.
(4) Saw cutting method-this cutting method has the best cutting quality, and is widely used for cutting alloy steel pipes, high pressure steel pipes, fluid seamless pipes, especially large diameter fluid seamless steel pipes and high alloy steel pipes. Sawing equipment includes bow saws, band saws and circular saws. Cold circular saws with high-speed steel fan blades are used for cold sawing alloy steel pipes; cold circular saws with hard alloy blades are used for cutting high alloy steel pipes.