With the introduction of kilowatt-level fiber lasers in the early 2000s and their subsequent integration into cutting tools in the late 2000s, fiber lasers have transformed laser cutting from a niche method to a mainstream fabrication process. Since then, fiber lasers have dominated the laser cutting of sheet metals because of their ease of integration, reliability, low maintenance, and low capital and operating costs versus prior laser technology, high cutting speeds, and the possibility of scaling up their power. The laser cutting market has grown more than 10 percent annually in the past decade, more than double the rate of other profile cutting processes.
In recent years, the fabrication industry has seen rapid adoption of ultra-high-power (UHP) fiber lasers in the range of 10 to 40 kW for cutting. By following state-of-the-art laser cutting systems each year on FABTECH’s exhibition floor or in its educational seminars, one would have noticed that the maximum power available for cutting has dramatically risen from 6 kW in 2016 to 40 kW in 2022, a nearly sevenfold increase in six years. In the past three years alone, the maximum laser power on cutting systems has jumped from 15 to 40 kW. The fast pace of UHP laser developments has continued this year, led by two notable recent developments: The availability of the 50-kW fiber laser for cutting and its testing in the field; and the release of high-efficiency UHP fiber lasers with electrical efficiencies of more than 50 percent, which offers significant energy savings for high-power cutting applications with high-duty cycles.
The overlapping of three major developments in the past few years has made the UHP cutting trend feasible, namely lowered cost/kW-power of fiber lasers, availability of cutting heads that can handle the ultra-high laser power, and better knowledge of application engineering regarding high-power laser cutting.
Cutting speeds dramatically rise with greater laser power, leading to a substantial reduction of operating costs (including gas usage, cycle time per part, and energy consumption per part) and significantly lower cost-per-part. Cutting speed of most stainless steel thicknesses, for example, more than quadruples by increasing power from 6 kW to 15 kW, while utilizing the same assist gas pressure and nozzle size (i.e., same gas flow) in both low- and high-power cutting, leading to a multiple-fold reduction in gas usage and other operating costs.
UHP lasers also allow for dross-free cutting of thick carbon steel and stainless steel with high-pressure air instead of more expensive nitrogen, or oxygen cutting that is much slower. Cutting with air-assist gas is significantly faster than oxygen cutting at high laser powers, as in air cutting—unlike with oxygen cutting—the speed scales up with laser power. For example, when cutting 16-mm thick carbon steel with a 30-kW laser, the cutting speed is greater than 9 m/min with air-assist gas, but is only about 2 m/min while using oxygen.