Question

which gas is considered to create the lowest amount of slag or dross, but also slightly decreases cutting capacity?

nitrogen
oxygen
argon
helium

Explanation:

Analyze plasma cutting gas characteristics

In plasma arc cutting, different gases affect the cut quality, dross (slag) formation, and cutting speed/capacity. Nitrogen, oxygen, argon, and helium are common choices, each with distinct thermal and chemical properties.

Evaluate nitrogen gas

Nitrogen provides excellent cut quality and is highly effective for cutting stainless steel and aluminum. It produces very low amounts of dross or slag on these materials, resulting in clean edges, though it can slightly decrease the maximum cutting capacity compared to highly reactive gases like oxygen on carbon steel.

Evaluate oxygen gas

Oxygen is primarily used for cutting carbon steel because it reacts exothermically with the iron, which actually increases cutting speed and capacity. However, it is not associated with decreasing cutting capacity.

Evaluate argon and helium

Argon is very heavy and inert, usually mixed with other gases rather than used alone for primary cutting because of its low energy density. Helium has high thermal conductivity but is expensive and typically used in mixtures to increase speed on thick non-ferrous materials, rather than being characterized by a slight decrease in capacity with minimal dross.

Select the correct option

Nitrogen is the standard gas recognized for producing the cleanest, lowest-dross cuts on non-ferrous metals while offering a slightly lower cutting capacity compared to oxygen-assisted cutting.

Answer:

• Nitrogen (Correct answer)
• Oxygen
• Argon
• Helium