Question

what is the minimum percentage of argon thats required to achieve a spray transfer on carbon steel?

90%
70%
80%
100%

Explanation:

Analyze the question and table

The question asks for the minimum percentage of Argon required to achieve a spray transfer on carbon steel.

Examine the table data

Using the GMAW Transfer Modes and GMAW Shielding Gas Effects knowledge points:

• Look at the "Carbon Steel" section of the table.
• Locate the "Spray Transfer" column.
• Identify the rows where the rating is "R" (Required) or "C" (Capable) for Spray Transfer:
• Row 1: \(100\%\text{ CO}_2\) is rated "NR" (Not recommended).
• Row 2: \(75\%\text{ Argon} + 25\%\text{ CO}_2\) is rated "NR" (Not recommended).
• Row 3: \(80\%\text{ Argon} + 20\%\text{ CO}_2\) is rated "C" (Capable).
• Row 4: \(\text{Argon} + 2\text{--}5\%\text{ Oxygen}\) (which contains \(95\text{--}98\%\text{ Argon}\)) is rated "R" (Required).
• Row 5: \(\text{Argon} + 10\text{--}15\%\text{ CO}_2\) (which contains \(85\text{--}90\%\text{ Argon}\)) is rated "R" (Required).

Determine the minimum percentage

The lowest percentage of Argon listed under Carbon Steel that is capable of achieving a spray transfer is \(80\%\) (Row 3: \(80\%\text{ Argon} + 20\%\text{ CO}_2\), rated "C"). Any mixture with less Argon (such as \(75\%\text{ Argon}\) in Row 2) is rated "NR" (Not recommended) for spray transfer. Therefore, the minimum percentage of Argon required to achieve spray transfer is \(80\%\).

Answer:

• 90%
• 70%
• 80% (Correct answer)
• 100%