Certified Welder Base and Filler Metals 2

Question 1

Which AWS filler metal classification designates an electrode suitable for welding low-alloy, high-strength steel?

Accepted Answer

E7018

Answer

E7018 is a low-hydrogen electrode designed for high-strength, low-alloy steels requiring good toughness.

Question 2

What does the 'R' designation indicate in an ER70S-6 filler wire classification?

Accepted Answer

Rod or electrode

Answer

The 'R' in ER70S-6 indicates the wire can be used as either a rod or an electrode.

Question 3

A base metal with a carbon equivalent (CE) above 0.45% typically requires which precaution?

Accepted Answer

Preheat before welding

Answer

High carbon equivalent increases hardenability and crack risk, so preheating is required to slow the cooling rate.

Question 4

Which stainless steel series is considered non-hardenable by heat treatment?

Accepted Answer

Austenitic (300 series)

Answer

Austenitic stainless steels cannot be hardened by heat treatment because they remain face-centered cubic at all temperatures.

Question 5

When welding dissimilar metals such as carbon steel to stainless steel, which filler metal is most commonly recommended?

Accepted Answer

E309L

Answer

E309L is formulated for joining dissimilar metals, especially carbon steel to stainless steel, due to its high alloy content.

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