As a knife that can cut iron like mud, laser continues to play a prominent role in the metal cutting market, especially in the cutting of thick metal plates. In the past, the cutting of thick metal plates mostly used CO2 lasers or plasma cutting. With the continuous rise of the power of fiber lasers, the megawatt ultra-high power fiber lasers have gradually developed into the main force in the field of thick metal cutting in a more efficient way.

In the past three years, the maximum power of fiber lasers used in metal cutting equipment has increased by 2.5 times; In the past 6 years, the maximum power of fiber lasers used in cutting equipment has increased by 7 times! The 50kW high brightness fiber laser has pushed the application of ultra-high power fiber laser cutting to a new height. In addition to the obvious advantages brought by the increase of cutting speed, 50kW laser can significantly improve the cutting ability of thick plates under different auxiliary gas processes: it can achieve high-quality cutting of 30-50mm carbon steel with air; For cutting stainless steel, the limit thickness of air/nitrogen cutting reaches 300 mm, and the limit thickness of oxygen cutting reaches 100 mm.

Ultra-high power fiber laser is changing the way of steel cutting. Using air-assisted cutting process to replace nitrogen and oxygen cutting process can also achieve high-quality, high-speed and economic cutting. The 100kW single-mode laser is used to cut and weld metal with thickness of 50 mm and above. The optical diameter of this laser is adjustable. The two applications can be realized by using the same equipment, which greatly reduces the production cost. Some leading manufacturers in the laser field are also exploring the high power metal cutting market and providing corresponding products and solutions for this market.

A new process for cutting stainless steel

Carbon steel can be cut with oxygen, nitrogen or air as auxiliary gas. Although oxygen cutting is good at cutting thick carbon steel with low laser power, it will reduce production efficiency because the cutting speed is not proportional to the laser power. On the contrary, when air is used to assist cutting, the speed is proportional to the power.

At lower power and speed, the thickness that can only be cut with oxygen in the past can now be cut with air-assisted UHP laser, and the speed can be several times faster, and the cutting quality is good. For low-power lasers, air cutting will lead to difficult removal of hang-ups and poor surface quality. The new efficient UHP cutting scheme provides better solutions for industries that rely heavily on thick plate processing (such as heavy industry), and is widely welcomed by the market.

Improve the thickness output and quality of thick plate cutting

With the increase of UHP laser power, the cutting thickness ability also increases.

In the continuous wave (CW) full-speed cutting mode, use 20 kW power slag-free air to cut 20 mm thick carbon steel, 40 kW power slag-free air to cut 30 mm thick carbon steel, and 40 kW power slag-free air to cut 40 mm thick carbon steel. For cutting stainless steel, it is easier to achieve slag free effect, so the limit cutting thickness is thicker than carbon steel. For continuous nitrogen and air cutting, slag free cutting and good cutting surface can only be achieved within a certain thickness under any given power. If it exceeds a certain thickness, pulse cutting (slower than continuous cutting) should be used to achieve qualified cutting quality: otherwise, the laser power must be increased. Generally, the cutting speed lower than 2m/min means that in continuous mode, the laser power is insufficient and it is difficult to achieve the best cutting quality.

For carbon steel oxygen cutting, on the premise of meeting the requirement of "smooth cutting surface", increasing power will increase the limit cutting thickness.

Faster and cleaner perforation

By using the peak power of UHP laser in pulse mode, the thick metal can be perforated quickly, and the splash generated is very small. The perforation time of 16mm thick stainless steel is greatly reduced from 6kW>ls to 0.5s of 10kW and 0.Is of 20kW. In practical applications, the perforation of s0. Is is usually regarded as "instantaneous".

Higher peak power increases the depth-width ratio of the molten pool, which makes it possible to connect the thickness faster through less transverse melting. The reduction of material transverse melting also minimizes the splash on the top surface.

The continuous increase of fiber laser power has greatly improved the applicability and production efficiency of laser cutting technology. At the same time, it is not inferior in processing quality, which is important for railway and heavy machinery. It is also good news for many industries that need to use thick metal plates, such as steel manufacturing. With the continuous transformation and upgrading of the industry, laser, as an advanced processing tool, will play an increasingly important role in the metal processing industry.

About HGTECH: HGTECH is the pioneer and leader of laser industrial application in China, and the authoritative provider of global laser processing solutions. We have comprehensively arranged laser intelligent machine, measurement and automation production lines, and smart factory construction to provide overall solutions for intelligent manufacturing.