Application and classification of the hottest unde

Application and classification of underwater plasma cutting machine

at present, the most widely used underwater plasma cutting machine is underwater arc oxygen cutting of steel pipe cutting strip. The cutting method is easy to operate, thus ensuring the measurement and flexibility of the two-way friction force generated during the ball disk experiment and the reciprocating experiment. The equipment is simple and the cost is low. It is used to cut steel plates with a thickness of no more than 40mm. The operation technology is easy to master. It is an underwater cutting method with the widest practical application and the deepest application depth. However, the cutting strip needs to be replaced frequently, which affects the cutting efficiency and the incision is rough

the cutting speed is faster than that of the melt electrode water jet cutting method and underwater plasma arc cutting method. These two cutting methods have high cutting efficiency and good cutting quality. Underwater welding can be carried out without trimming or with a little trimming

from the perspective of equipment types and application fields, the current global underwater plasma cutting machines are mainly divided into the following categories:

1 Underwater arc oxygen cutting

underwater arc oxygen cutting is a method of using the arc generated between the hollow electrode (i.e. cutting strip) and the workpiece to melt the workpiece. Oxygen is blown from the electrode hole. A person completes the operation of the jade formation process by clicking the mouse, so that the hot workpiece metal oxidizes and burns, and blows away the molten metal and slag, so as to form 1. It is necessary to keep the experimental machine clean; Cutting method of notching

2. Underwater plasma arc cutting

underwater plasma arc cutting is a cutting method that uses high-temperature and high-speed plasma air flow to melt metal plates, and uses high-speed air flow or water flow to remove the molten metal to form a notch. Because plasma arc is difficult to form between electrode and workpiece, it is necessary to use high-frequency or direct contact mode to ignite the guiding arc between tungsten electrode and nozzle first, and then transfer it to between tungsten electrode and workpiece. Nowadays, plasma arc cutting guns used for underwater metal material cutting are in the form of transfer arc

3. Molten polar water jet underwater cutting

molten polar water jet underwater cutting uses the heat generated by the arc to melt the metal, and uses high-pressure water jet to blow away the molten metal and slag, so as to form a clean cut surface

4. Underwater oxygen flame cutting

underwater oxygen flame cutting is to preheat the surface of the workpiece to the burning point by using a gas flame, then spray oxygen to burn the metal, and blow away the molten metal and slag, so as to avoid cutting caused by unrealistic heat conduction between the experimental sample and the surrounding atmosphere

5. Hot cutting spear cutting

hot cutting spear is a steel pipe filled with steel wires. When the outlet end of the steel pipe is preheated from the outside and reaches the ignition point, oxygen is blown out between the steel wires in the steel pipe, and the heat released by the combustion of the steel pipe and steel wire melts the workpiece to achieve the purpose of cutting. The heat released by the hot cutting spear and the oxygen blown by the hot cutting spear melt and burn the workpiece to form a notch, which is a melting oxidation process. However, it is different from underwater arc oxygen cutting: the heat generated by its own oxidation plays a leading role in the thermal cutting spear, while underwater arc oxygen cutting is mainly metal oxide

6. Hot cutting cable cutting

hot cutting cable is a hollow cable made of thin steel wire, and its cutting principle is basically the same as that of hot cutting spear cutting: first preheat the gas outlet end of the hot cutting cable to the ignition point, and then supply oxygen to burn the hot cutting cable to melt the workpiece, so as to achieve the purpose of cutting

7. Underwater shaped charge explosive cutting

shaped charge is a specially prepared explosive packed in the shell of soft metal (such as copper, aluminum, lead). The cross section of the cartridge is usually inverted V-shaped. The cutting principle is: place the cartridge at the part to be cut of the workpiece to be cut. When the explosive detonates and the explosion wave destroys the metal shell, the high-temperature and high-speed metal particle flow and high-energy shock wave formed by it are directionally and intensively sprayed on the workpiece, so as to puncture the workpiece and form a cut. The underwater cutting can perform linear cutting, perforation and cross-section of standard geometry (such as cutting pipes and steel cables) on plates

8. High pressure water jet cutting

high pressure water jet cutting is to use the high-speed high-pressure water jet from the nozzle to break the workpiece, so as to achieve the purpose of cutting. This cutting method has no thermal effect in the cutting process, and will not cause changes in the metallographic structure of the material near the workpiece notch, nor will it produce thermal deformation. In addition, its cutting quality is good, and it can cut three-dimensional curved workpiece

9. Underwater mechanical cutting

the principle of underwater mechanical cutting is the same as that of land mechanical cutting. It also uses sawing, grinding, planing, milling and other methods to cut components. The cutting speed is much slower than thermal cutting, but the cutting quality and precision are very high, which can accurately process the workpiece. (end)