The evaluation of the cutting quality of CNC plasma cutting machine mainly includes the following aspects:

1. The amount of hanging slag:

It is a tool to describe the oxide slag or re-solidified material that adheres to the lower edge of the incision after thermal cutting. The level of dross is usually determined by visual observation, and is generally described in terms of none, minor, moderate and severe.

In addition, there should also be corresponding requirements for the straightness of the cutting seam, the condensation degree of the upper edge and the notch of the CNC plasma cutting machine.

2. The width of the incision: It is one of the most important characteristic values for evaluating the cutting quality of the CNC plasma cutting machine, and it also reflects the radius of the smallest circle that the cutting machine can cut. It is measured by the size of the widest part of the incision. Generally speaking, the incision width of the plasma cutting machine is between 0.15-6mm.

  influence:

1. When the cutting thickness increases, it is often necessary to use a larger nozzle aperture, and the incision will also be widened.

2. The increase in the width of the incision will increase the deformation of the cut piece.

3. Too wide incision will not only waste materials, but also reduce the cutting speed and increase energy consumption.

4. The width of the incision is mainly related to the diameter of the nozzle. Generally speaking, the width of the incision is always 10%~40% larger than the diameter of the nozzle.

3. Surface roughness:

It is used to describe the appearance of the incision surface, and determine whether it needs to be reprocessed after cutting. It is the Ra value measured on the cross section at 2/3 of the depth of the incision. As a result of the action of the cutting air flow which produces longitudinal vibrations in the direction of travel of the cutting, the main way is cutting corrugations. The surface roughness after cutting by oxyacetylene method is generally required: Grade 1 Ra≤30μm, Grade 2 Ra≤50μm, Grade 1 Ra≤100μm. The kerf Ra value of plasma arc cutting usually exceeds that of flame cutting, but is lower than the Ra value of laser kerf (less than 50μm)

4. The squareness of the incision edge:

It is also an important parameter reflecting the cutting quality of CNC plasma cutting machine, which is related to the level of reprocessing required after cutting. This indicator is often expressed as verticality U or angle tolerance. Generally speaking: the U value of plasma arc cutting is closely related to the plate thickness and process parameters, usually U≤(1%~4%)δ (δ is the plate thickness), and U≤0.5mm for laser cutting.

5. The width of the heat affected zone:

This index is very important for those low alloy steel or alloy steel that can be hardened or heat treated. Too wide heat affected zone width will significantly change the performance near the incision. The width of the heat-affected zone of air plasma arc cutting is about 0.3mm. When underwater plasma arc cutting, the width of the heat-affected zone of CNC plasma cutting machine can be narrower.