The main factors that affect the cutting process (including cutting speed and quality) are: the purity of the cutting oxygen, the flow rate, flow rate and pressure of the cutting oxygen, the shape of the cutting oxygen flow, the cutting inclination, the power of the preheating flame, the composition of the metal being cut and performance, etc.
In the cutting process, the cutting oxygen flow plays a leading role. On the one hand, it burns the metal, and on the other hand, it blows the slag from the combustion away from the cut. Therefore, some parameters related to cutting oxygen flow, such as purity, flow rate, flow rate, pressure and oxygen flow shape are the main parameters that affect the cutting process.
1. The purity of the cutting oxygen of the fiber laser cutter
The higher the purity of the cutting oxygen, the faster the combustion reaction and the faster the cutting speed. If the oxygen purity is poor, not only the cutting speed will be greatly reduced, the cutting quality will be deteriorated, but also the oxygen consumption will increase.
For example, reducing oxygen purity from 99.5% to 98% reduces cutting speed by 25% and increases oxygen consumption by 50%. It is generally believed that when the oxygen purity is lower than 95%, gas cutting cannot be carried out. In order to obtain a gas cutting incision without sticky slag, the oxygen purity needs to reach more than 99.5%.
2. Cutting oxygen flow of fiber laser cutter
In order to complete gas cutting, a sufficient amount of oxygen needs to be supplied to the reaction. If the oxygen flow is insufficient, the metal cannot be fully burned, which is likely to cause sticky slag and slow the cutting speed. Too much oxygen flow will make the metal cold zone, easily cause slag, and even cause insufficient preheating of the metal, which will interrupt the cutting.
With the increase of oxygen flow, the cutting speed gradually increased. For a good quality cut, with the increase of oxygen flow, the cutting speed gradually increases, but exceeds a certain limit value, the cutting speed decreases instead. Therefore, there is an optimal oxygen flow value for a certain steel plate thickness, at this time not only the cutting speed is the highest, but also the cutting surface quality is good.
3. Cutting oxygen pressure of fiber laser cutter
As the cutting oxygen pressure increases, the cutting oxygen flow increases correspondingly, and the ability to remove sticky slag increases, so the thickness that can be cut increases accordingly. However, when the pressure increases to a certain value, the thickness that can be cut also reaches the maximum value. If the pressure is increased again, the thickness that can be cut decreases.
When cutting with an ordinary cutting nozzle, when the pressure is low, the cutting speed increases with the increase of the pressure, but when the pressure exceeds 0.3mpa, the cutting speed decreases instead. When cutting with a diffusion type cutting nozzle, if the cutting pressure conforms to the design pressure of the cutting nozzle, when the pressure increases, the cutting speed is also increased compared with the ordinary cutting nozzle because the flow rate and momentum of the cutting oxygen flow also increase.
4. Cutting oxygen flow shape of fiber laser cutter
In order to make the incision width consistent up and down along the thickness direction and obtain good cutting quality, the cutting oxygen flow is required to maintain a cylindrical shape within the longest possible range, with a clear boundary line and straight and powerful. If the wind line is thick and the boundary line is blurred, not only the speed will decrease, but also the quality of the cutting surface will deteriorate, and the slag will adhere to the lower edge of the incision.
5. Cutting inclination of fiber laser cutter
As the cutting inclination increases, the cutting speed increases. When the cutting inclination angle reaches a certain limit angle, the cutting speed reaches the maximum value, and if the cutting inclination angle continues to increase, the cutting speed decreases instead. The type of cutting nozzle and the thickness of the steel plate to be cut both affect the cutting inclination angle when the cutting speed of the China fiber laser cutting machine reaches the maximum value.
6. Preheating flame energy rate of fiber laser cutter
If the flame is too strong, the upper edge of the incision may collapse, and bead-like droplets may adhere, the quality of the cutting surface will deteriorate, and the lower edge of the incision will stick to slag. If the flame is too weak, the cutting speed will be slowed down, and problems such as cutting interruption, tempering, and increased back drag will easily occur.
7. The initial temperature and surface state of the steel plate of the fiber laser cutter
The high initial temperature of the steel plate can speed up the cutting speed and significantly reduce the consumption of cutting oxygen.
When there is thick oxide scale, yellow rust and other dirt on the surface of the steel plate, the cutting speed will be reduced, and the cutting will be interrupted in severe cases.
8. Slag viscosity of fiber laser cutter
The slag has low viscosity and good fluidity, which is easy to be blown away by the cutting oxygen flow, and the cutting speed can be accelerated.