How to avoid plasma cutting defect skills?

1. The upper edge is rounded. Caused by the plasma arc heat on the top surface of the incision. Reasonable control of the cutting torch height can minimize or eliminate the upper edge rounding phenomenon. Severe upper edge rounding phenomenon usually indicates that the cutting height of the torch needs to be reduced.

2. Upper edge slag. The upper edge slag is caused by fast cutting or the cutting gun height is set too high. Slowing down the cutting speed or lowering the cutting height of the torch can reduce the upper edge slag. The upper edge slag is easy to remove.

3. Dregs on the bottom. Molten metal may accumulate on the bottom of the sheet. The faster the cutting speed, the less the amount of material melted, and the less the accumulation of slag at the bottom. (Follow WeChat public account: Material Science and Engineering) If the bottom slag is easy to remove, it indicates that the cutting speed is slow; while the bottom slag that is difficult to remove or even needs to be removed by polishing means indicates that the cutting speed is too fast .

4. Incision. The cutting table lists the cutting width parameters, which can be used as a reference for cutting programming. The width of the cut is related to the size of the cutting nozzle. The higher the cutting current, the larger the width of the cut; in addition, the higher the height of the cutting gun, the larger the width of the cut.

5. Bevel angle of groove. The bevel angle formed by high-precision cutting is in the range of 0-3°, while ordinary plasma cutting will form a larger bevel angle. Proper and reasonable control of the cutting gun height can minimize the size of the bevel angle of the bevel, and also improve the width of the cut and the top edge collapse and round corners. When rounding or cutting corners, a slower cutting speed can be used to reduce the size of the bevel angle.

6. Cutting speed. The cutting table provides information on the optimal cutting speed. All plasma systems can perform fast or slow cutting, but the cutting effect is different. When cutting at a corner or in a narrow space, the cutting speed should be reduced to reduce the size of the bevel angle and the rounding phenomenon.

7. The optimal cutting speed can form a slightly visible trailing arc on the cutting section. When cutting mild steel, the cutting speed can be evaluated by observing these arcs, but the situation is different for aluminum and stainless steel. When air or oxygen plasma cutting is used, the trailing arc with the deflection angle less than 15° indicates that the cutting speed is in the best range. When using high-precision cutting technology, the best cutting quality can be accompanied by an almost vertical arc. Slow cutting can form an arc that is skewed forward, while fast cutting can form an arc that is at an acute angle to the top surface of the sheet.

8. Nitride layer accumulation. Air plasma will produce nitride layer contamination on the cutting surface when cutting carbon steel and stainless steel. The surface of the nitride layer needs to be polished before welding to avoid weld pores.

9. Cutting section. The cutting method and the accuracy of the positioner are the most important factors that affect the quality of the cutting section. (Follow the WeChat public account: Material Science and Engineering) Therefore, in order to obtain the best cutting section, the cutting method must be correctly selected according to the actual material type.

10. Adopting non-air plasma cutting method can avoid the accumulation of nitride layer. Carbon steel cutting can use oxygen plasma, and non-ferrous metal cutting can use H35 or nitrogen/water mist protective gas cutting methods.