Types of flames for gas welding and cutting
The flame used in gas welding heats, melts and welds the part, while in gas cutting it serves as a preheating source. Acts as a protective medium for melting metal.
The quality and productivity of gas welding and cutting largely depend on choosing the right flame.
The welding flame must have sufficient temperature, be small in volume and have a straight core for concentrated heat.
Furthermore, it must be protective enough to prevent oxidation and pollution caused by oxygen and nitrogen in the air.
The angle of inclination between the cutting nozzle and the workpiece has a direct impact on the gas cutting speed and rear drag. If the inclination angle is not chosen properly, not only will it fail to improve the gas cutting speed, but it will also increase oxygen consumption and even cause difficulties in gas cutting.
Distance between the cutting nozzle and the surface of the part
Generally, the distance between the flame core and the surface of the part should be maintained in the range of 3-5 mm, which provides ideal heating conditions and minimizes the possibility of carburization.
If the flame core touches the surface of the workpiece, it will not only cause melting on the upper edge of the cutting groove, but also increase the possibility of carburizing the cutting groove.
In general,
- when cutting thin sheets, due to the faster cutting speed, the flame can be larger and the distance between the cutting nozzle and the workpiece surface can be larger;
- When cutting thick plates, due to the slower gas cutting speed, to avoid melting at the upper edge of the cutting groove, the preheating flame should be shorter and the distance between the cutting nozzle and the workpiece surface should be a little smaller, which can maintain the straightness of the cutting oxygen flow and the purity of oxygen, thus improving the cutting quality.
