Chapter Six Exam Flashcards
(25 cards)
Small additions of carbide formers such as vanadium, niobium and titanium are added to chromium-molybdenum steels for higher temperature service. What is the purpose of these elements? (Multiple Choice)
Precipitation strengthening and grain refinement.
Covered electrodes that use basic coatings: (Multiple Choice)
Reduce oxygen content of weld.
The restraint afforded to overall weld metal shrinkage is usually higher in: (Multiple Choice)
Thick plates and groove welds.
Since creep failure is a condition that occurs at grain boundaries, what aspect of these grain boundaries increases creep strength? (Multiple Choice)
Smaller grain size improves creep strength by increasing grain boundary area? WRONG.
During a welding procedure, the welder increases the amperage more than the indicated values. As a result of this change, what would be the effect on weld toughness? (Multiple Choice)
Toughness of weld and HAZ decreases.
What kind of steels may be selected for low-temperature service, down to -196 Deg C, and what is a key alloying element? (Multiple Choice)
Ferritic cryogenic steels with nickel in the range 1.5-9.0.
With stress relief heat treatment, what material properties can be expected to change from the as-welded product? (Multiple Choice)
Joint tensile strength will be reduced.
High energy input welds typically result in: (Multiple Choice)
Large ASTM grain size? WRONG. Thin grains maybe?
What are the critical parameters required to calculate energy input in a weld? (Multiple Choice)
Volts, amp, travel speed.
What is the difference between weld metal microstructure in a carbon steel and the parent plate? (Multiple Choice)
Weld metal cooling rate is usually much more rapid than that of a plate after rolling at the mill.
CSA W59 dictates that E4918 SMAW electrodes that are left out of holding ovens for more than four hours need to be: (Multiple Choice)
Baked for a defined temp and time before use or discarded.
If NDE is called for on a weld that has been defined as having a high probability of producing hydrogen-induced cold cracking, which of the following applies? (Multiple Choice)
NDE must take place not less than 48 hours after joint completion.
The solidification structure that results from a slow welding speed can be described as: (Multiple Choice)
Short weld pool with solidifying crystals growing from the back of the pool.
According to CSA W59, the SAW process can be used without preheat if adequate energy input is ensured. This is applicable when making: (Multiple Choice)
Fillet welds in multiple passes?WRONG
For aqueous corrosion, which pH is most aggressive to steel? (Multiple Choice)
Acidic.
What elements are incorporated into weathering steels to reduce the corrosion rate in certain environments? (Multiple Choice)
Vanadium and zinc? WRONG
Lamellar tearing is most likely to occur in which of the following? (Multiple Choice)
Thick T grooves.
In arc welding, the area of the base metal adjacent to the fusion line that is not melted is called: (Multiple Choice)
HAZ.
What is a common and accepted way of reducing the probability of solidification cracking in a weld? (Multiple Choice)
Control depth to width ratio of weld beads in range of 0.5-1.0.
On a thin plate, the cooling rate is more sensitive to heat input and doubling the heat input will: (Multiple Choice)
Reduce the cooling rate by four times.
Which of the following processes generate the highest rate of dilution?
SAW.
Why are the tests from the Welding institute of Canada waiting 24 hours for results?
Crack delay.
Processes that are not hydrogen controlled may require: (Multiple Choice)
Higher preheat temperatures for thicker plates.
Heat input from welding: (Multiple Choice)
Determines the amount of component distortion during phase transformations? WRONG
