CNC plasma cutting of stainless steel, a few things you must know

When using a CNC plasma cutting machine to cut stainless steel plates, due to some characteristics of stainless steel itself, we should not copy some of the original experience of cutting ordinary carbon steel plates into stainless steel plasma cutting work. The cutting current should be appropriately increased, the compressed air pressure should be increased, and the cutting speed should be reduced. If the cutting effect is high, inert gases such as nitrogen can be used for protection.

 

When using thermal cutting processing, a very common problem is slag on the cutting surface, which is the cutting flatness problem we will talk about. As for CNC plasma cutting machines, a similar situation still exists. At the same time, considering that CNC plasma cutting machines are currently mainly used for cutting special materials such as stainless steel, the slag treatment is more difficult than for carbon plates, which is difficult for some precision materials. For processing companies or users who want to reduce secondary processing, how to reduce slag residue and improve cutting flatness quality is believed to be a concern for many companies.

 

In order to improve product quality and taste, more and more companies are using stainless steel plates in their products, such as kitchenware, cookware and other products. When using stainless steel plates, you will inevitably encounter problems with the cutting and processing of stainless steel plates. At present, the main cutting and processing methods for stainless steel plates include: laser cutting, CNC plasma cutting, CNC punching, etc.

 

Different processing methods will differ in terms of processing thickness, processing speed, processing quality and processing cost. Generally speaking, laser processing has the best effect and is more suitable for stainless steel sheet cutting and processing. The equipment purchase cost and processing cost are the highest. The processing effect of CNC punch press is second, and the equipment purchase cost is between laser cutting machine and CNC plasma cutting machine. The processing effect of plasma cutting is average, the cutting edge will be slightly discolored, the processing speed is fast, the equipment purchase cost and processing cost are the lowest, and it is more suitable for use in situations where the cutting effect is not high.

 

Literally understood, the so-called flatness of the cutting surface refers to the distance between the highest point and the lowest point on the cutting surface of the measured part and two parallel lines drawn according to the inclination direction of the cutting surface.

 

Generally speaking, there is a molten layer about 0.25 to 3.80mm thick on the cutting surface processed by a CNC plasma cutting machine. The residual chemical composition of the slag of this thickness is consistent with the material itself, including the chemical composition of the cutting surface. . For example, when we are cutting aluminum alloys containing magnesium, if the magnesium metal content is 5%, after analyzing the slag residue, the magnesium content in its composition will remain unchanged. Even if the slag residual thickness reaches 0.25mm, there will be no There are oxides. If the cutting surface is used for welding directly, a dense weld can also be obtained. When cutting stainless steel, because the heated area quickly passes the critical temperature of 649°C, chromium carbide will not precipitate along the grain boundaries. Therefore, cutting stainless steel with plasma arc will not affect its corrosion resistance. In other words, the slag residue within the allowable range does not affect the physical properties of the cutting material, but can be achieved by adjusting the working gas pressure of the CNC plasma cutting machine and the walking speed of the cutting torch to reduce the thickness of the slag.