Laser cutting common problems analysis and answer

The principle of laser cutting metal materials is to use the energy released when the laser beam irradiates to the surface of the steel plate to melt and evaporate the metal. 

For the manufacturing industry that uses stainless steel sheet as the main component, the use of laser cutting stainless steel is a fast and effective processing method.

However, laser cutting machine will always encounter some problems in the process of cutting stainless steel, resulting in poor cutting quality, 

and the most important process affecting the quality of metal cutting is cutting speed, laser power, air pressure, etc., 

so solve the common problems of stainless steel laser cutting to start from the process, if the process parameters of the laser cutting machine are strictly controlled in the processing process, 

It can ensure the machining quality of the workpiece. This paper will be combined with our company's customers in the actual production of some problems to summarize, analyze the reasons and propose solutions

1.What factors affect the absorption of laser energy by the processed material?

When laser processing materials, the material will absorb laser energy, due to the internal structure and composition of the material material is different, the absorption of laser is not the same, laser wavelength, material conductivity, surface roughness and coating will affect the absorption of laser energy of the material.

2.Abnormal spark occurs when cutting mild steel.

When mild steel is cut normally, the flame beam is long and flat, and rarely splits. The appearance of abnormal spark will affect the finish of the cutting section of the part.

In this case, if the other parameters are normal, consider:

① The laser head nozzle loss is serious, should be replaced in time.

② When the new nozzle is not replaced, the working gas pressure should be increased

③ If the screw at the joint of the nozzle and the laser head is loose, stop cutting immediately, check the connection status of the laser head, and tighten the screw again.

3.The laser is not fully penetrated.

① The selection of the laser head nozzle does not match the thickness of the processing plate.

② The laser cutting line speed is too fast, and it is necessary to reduce the line speed by operation control.

4.When laser cutting processing stainless steel and aluminum coated zinc plate, the workpiece has burrs.

First of all, consider the burr factor when cutting low carbon steel, but it is not possible to simply speed up the cutting speed, 

because the increase in speed sometimes occurs when the plate is cut without wearing, which is particularly prominent in the processing of aluminum coated zinc plate. 

At this time, other factors of the machine tool should be comprehensively considered to solve, such as whether the nozzle should be replaced, and the guide rail movement is unstable.

① The laser focus position offset is adjusted according to the offset of the laser focus.

②The output power of the laser is not enough. It is necessary to check whether the laser generator is working properly. If normal, observe the laser control button output value is correct.

③ The cutting line speed is too slow, and the cutting line speed should be improved when the operation is controlled.

④ Cutting gas purity is not high, can not provide high-quality cutting gas.

⑤ The machine running time is too long, resulting in instability. At this point, you need to shut down and restart.

5.How to choose the puncture point in laser cutting processing.

Through the action of the laser beam will form a crater in the material, at the same time, the generated air will form a hole in the material, 

which is what we call the puncture point. When in the process of penetrating the steel plate, the cutting speed of the laser beam will change greatly, and the cutting will be finally completed.

Generally, when the surface cutting fracture is not required for the design part, manual processing can be done without laser cutting programming, 

so that the control software automatically generates the puncture point. However, when the design has high roughness requirements for the cutting section of the parts to be processed, 

it is necessary to pay attention to this problem, which usually requires manual adjustment of the starting position of the laser beam when programming the laser cutting program, that is, manual control of the puncture point. 

It is necessary to move the puncture point originally generated by the laser program to the required reasonable position to meet the requirements of the surface accuracy of the machined parts.