Certified Welder Base Metal Preparation 2

Question 1

When preparing stainless steel for welding, which cleaning agent should be avoided to prevent contamination?

Accepted Answer

Chlorinated solvents

Answer

Acetone

Answer

Isopropyl alcohol

Answer

Mild detergent

Question 2

What is the primary purpose of beveling the edges of thick base metal before welding?

Accepted Answer

To ensure full penetration and fusion

Answer

To reduce distortion

Answer

To speed up the welding process

Answer

To improve surface appearance

Question 3

Which condition on a base metal surface will most directly cause hydrogen-induced cracking in the weld?

Accepted Answer

Moisture or water

Answer

Light surface rust

Answer

Mill scale

Answer

Paint overspray

Question 4

For a butt joint in ¾-inch carbon steel plate, a double-V groove is preferred over a single-V groove primarily because:

Accepted Answer

It reduces total weld metal required and distortion

Answer

It is faster to cut

Answer

It eliminates the need for back gouging

Answer

It allows higher travel speed

Question 5

A welder notices blue-gray discoloration on the surface of carbon steel plate. This most likely indicates:

Accepted Answer

Heat tinting from prior thermal cutting

Answer

Oil contamination

Answer

High carbon content

Answer

Galvanized coating

Question 6

When using a grinding wheel to prepare a weld joint, the wheel used on stainless steel should:

Accepted Answer

Be dedicated to stainless steel only

Answer

Be the same wheel used on carbon steel

Answer

Contain iron-based abrasives

Answer

Be run at the highest possible RPM

Question 7

What minimum preheat temperature is typically required for high-carbon steel (0.45% C) before welding to prevent cracking?

Accepted Answer

300–400°F (149–204°C)

Answer

No preheat required

Answer

100°F (38°C)

Answer

600°F (316°C)