Process upgrade 1.0: from plasma to laser
Before the popularization of laser applications, carbon steel medium and thick plates usually used traditional processes such as flame cutting, plasma cutting, and high-pressure water cutting, among which plasma cutting was the representative. Plasma cutting is a processing method that uses the heat of a high-temperature plasma arc to partially melt the metal at the incision of the workpiece, and uses the momentum of the high-speed plasma to remove the molten metal to form an incision. Plasma cutting can cut almost all types of metals with different working gases, and can also cut ultra-thick plates by adjusting the cutting current.
For plasma cutting, the cutting current of the plasma power supply and its most important cutting process parameters directly determine the thickness and speed of the cutting: the larger the current, the greater the plasma arc energy, the stronger the cutting ability, and the higher the cutting speed. However, the increase of the cutting current will also increase the diameter of the plasma arc, and the arc will become thicker, making the slit wider. At the same time, the excessive cutting current will increase the nozzle thermal load, and the cutting quality will decrease after the nozzle is damaged.
When processing medium and thin plates, plasma cutting has the advantages of fast speed and smooth end faces, but the thicker the material, the rougher the plasma cutting end faces and the worse the verticality. In addition, due to the wide diameter of the plasma arc, plasma cutting cannot cut precise small holes. With the rise of lasers, in response to the impact of laser cutting, the plasma cutting industry has developed fine plasma cutting equipment, which produces extremely compressed arcs by greatly reducing the size of the nozzle hole, greatly increasing the current density, and obtaining higher cutting accuracy and better The finish is high, but it still can’t achieve the effect of laser cutting. Laser cutting is gradually gaining market acceptance by virtue of higher speed, higher precision, and more environmental protection. In the early days when the laser power was low, laser cutting only had advantages in thin plate processing, and could not process medium and thick plates. In recent years, the laser power has continued to increase, from 6kW, to 8kW, 12kW, 15kW, 20kW, and then to 30kW. The power has been continuously improved, the technology has been continuously improved, and the bottleneck of laser cutting has been continuously broken.
Process Upgrade 2.0: Process iteration of laser cutting
Up to now, with the increase of laser power, carbon steel cutting has tempered four common processes, namely frosted surface cutting process, bright surface cutting process, air/nitrogen cutting process, and the latest oxygen rapid cutting process. OFweek Laser Network and Chuangxin Laser Application Center used Chuangxin Laser 20kW laser to cut 20mm carbon steel materials, and tested the cutting effect of various laser processes.
The early frosted surface cutting process used large nozzle oxygen cutting, with lower power, slower cutting speed, and larger taper of the workpiece. During the test, the Chuangxin laser output 2.1kW power, the cutting speed was 0.65m/min, and the single-sided taper of the sample was 0.5mm.