Are You Changing Consumables Frequently? Here’s Why

If you find that you are going through consumables excessively, there are likely six reasons why.

1.You are changing your consumables at the wrong time. Many shops change consumables after a set number of pierces or during a shift change. The fact is, consumable wear is application-specific. Generally, you should replace standard all-copper electrodes when the hafnium pit depth reaches 0.040 in. Silver/hafnium interface electrodes can reach a pit depth of 0.080 in. safely before they need to be replaced.

2.Your torch is too far (or too close) to the workpiece. See the previous sections regarding cut and pierce height.

3.The arc is stopping at the wrong time. Make sure your torch remains over the plate when the cut ends. If the arc terminates abruptly because it runs off the plate, an excessive amount of hafnium can be ejected, translating into a loss of 10 to 15 arc starts.

4.Your gas supply is too low. This is probably the most common cause of excessive consumable wear. Low flow rates can lead to catastrophic, almost immediate nozzle destruction by causing the pilot arc to attach to the inside of the nozzle orifice.

5.Not enough coolant is flowing to the torch. Proper coolant flow is essential to proper consumable wear. Flow restrictions reduce consumable cooling, which results in excessive heat buildup in the consumables and more rapid erosion.

6.You have a poor work cable connection. A good electrical connection is essential. With a good connection, arc transfer occurs within 100 milliseconds. A poor connection can delay that to 1⁄2 second or more, causing excessive consumable wear and misfiring.