resistance?
"When certain stainless steels are heated between 500-850° C, carbides form
at the grain boundaries and cause a local depletion of chromium."
(A) Oxidization
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, (B) Increased toughness
(C) Solution heat treatment
(D) Sensitization ANS >>> (D) Sensitization
Note; Also known as "carbide precipitation" -- Chromium binds to carbides, and
"sweats out" at the grain boundaries
2. On a radiograph, undercut appears as a line.
(A) light
(B) dark ANS >>> (B) dark
3. What is the Canadian Standard for safety in welding? ANS >>> CSA W117.2
4. What is the typical three-phase input voltage in most Canadian welding
shops? ANS >>> 600V
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, 5. True or False ANS >>> The cable from the workpiece back to the welding
machine is called the "ground lead". ANS >>> False. The correct term is the
"work lead".
6. What is the type of radiation that can damage living cells? ANS >>> Ionizing
7. Name two examples of ionizing radiation. ANS >>> X-rays and Gamma rays
8. What is the minimum suggested shade for a welding helmet when using
5/32 SMAW electrode at 150 A? ANS >>> Shade 10
9. Approx. how far could spatter travel when welding/cutting from 2.5m high?-
ANS >>> Possibly up to 6m
10. What is the toxic component contained in some copper alloys? ANS >>>
Beryllium
11. Which welding process will likely have the highest fume generation rate?
[SMAW / SAW / FCAW] ANS >>> FCAW
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, 12. What do the terms TLV and TWA stand for? ANS >>> TLV ANS >>>
Threshold limit value TWA ANS >>> Time weighted average
13. Is helium lighter or heavier than air? ANS >>> Lighter
14. The action of UV light on oxygen produces which toxic gas? ANS >>> Ozon
15. Which common fuel gas has the widest range where it can become flam-
mable when mixed with air? ANS >>> Acetylene
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