cap 4 Materiales

Question 1

1. Iron tapped from the blast furnace during the initial refining process from a mixture of iron ore, hematite, magnetite, coke, and limestone is referred to as:

a. billet.
b. slab.
c. ingot.
d. pig iron.

Answer 1

d. pig iron.

Question 2

2. As a result of the natural conditions inside a blast furnace, pig iron always contains:

a. less than 2% carbon.
b. 3 to 4% carbon.
c. 4 to 6% carbon.
d. more than 6% carbon.

Answer 2

b. 3 to 4% carbon.

Question 3

3. Open-hearth, bessemer converter, electric arc, and basic oxygen are all examples of:

a. secondary steel refining furnaces.
b. blast furnaces.
c. primary ore refining furnaces.
d. forging equipment

Answer 3

a. secondary steel refining furnaces.

Question 4

4. When the carbon content of pig iron is reduced to less than 2% the resulting new material is generically called:
   a. cast iron.
   b. white. iron.
   c. gray iron.
   d. steel.

Answer 4

d. steel.

Question 5

5. The principle use for wrought iron is in the manufacturing of:

a. welded pipe.
b. plate steel.
c. strip steel.
d. extruded steel shapes.

Answer 5

a. welded pipe.

Question 6

6. The majority of common carbon and low alloy steels can be described by a standardized code system developed by the American Iron and Steel Institute, which consists of a letter followed by four or five numbers.The letter refers to the:

a. carbon content of the steel.
b. steel manufacturing process used.
c. alloy content of the steel.
d. country of origin for the steel

Answer 6

b. steel manufacturing process used.

Question 7

7. As the carbon content of steel is increased from
   0.05% (low carbon). the strength of the material also increases. This increase in strength causes a loss of:

a. yield strength.
b. tensile strength.
c. hardness.
d. ductility.

Answer 7

d. ductility.

Question 8

8. _______are rarely hardened by heat treatment because their carbon content permits so little formation of hard martensite.

a. Alloy steels
b. Low carbon steels
c. Medium carbon steels
d. High carbon steels

Answer 8

b. Low carbon steels

Question 9

9. Steels that contain_______carbon contain sufficient carbon that they may be heat treated for desirable strength, hardness, machinability, or other properties.

a. 3 to 6%
b. 0.06 to 0.25%
c. 0.25 to 0.5%
d. 1.6 to 2.1%

Answer 9

c. 0.25 to 0.5%

Question 10

10. Carbon steel, classified as tool and die steel, in which hardness is the principle property desired, is referred to as:

a. alloy steel
b. low carbon steel.
c. medium carbon steel.
d. high carbon steel.

Answer 10

d. high carbon steel.

Question 11

11. Alloying elements can affect all but which of the following properties?
    a. Weldability.
    b. Hardness.
    c. Corrosion resistance.
    d. Contrast.

Answer 11

d. Contrast.

Question 12

12. The addition of 5% nickel or more than 10%
    chromium greatly Increases the ability of the alloy to primarily:

a. resist fracture.
b. resist corrosion.
c. resist elongation.
d. resist creep.

Answer 12

b. resist corrosion.

Question 13

13. Which type of stainless steel is considered paramagnetic and cannot be inspected by magnetic particle testing?

a. Martensitic stainless steel.
b. Ferritic stainless steel.
c. Austenitic stainless steel.
d. Galvanic stainless steel

Answer 13

c. Austenitic stainless steel.

Question 14

14. One advantage of cast steel over wrought steel is
    that:

a. cast steel is isotropic.
b. wrought steel is isotropic.
c. cast steel is anisotropic.
d. wrought steel is anisotropic.

Answer 14

a. cast steel is isotropic.

Question 15

15. The two major categories of aluminum alloys are:

a. quenched and tempered.
b. cast and wrought.
c. heat-treated and age-hardened.
d. tempered and annealed.

Answer 15

b. cast and wrought.

Question 16

16. The density of aluminum is approximately_______ that of steel.
    a. one-quarter
    b. one-third
    c. one-half
    d. one-fifth

Answer 16

b. one-third

Question 17

17. Copper alloys exhibit a combination of corrosion resistance and thermal conductivity that makes them useful as:
    a. roofing material and drain piping.
    b. baking and cooking vessels.
    c. radiators and heat exchangers.
    d. vent ducting and drip collectors.

Answer 17

c. radiators and heat exchangers.

Question 18

18. Nearly three-quarters of all nickel produced is used for:
    a. plating material and as an alloying element in steel.
    b. plating material and the production of currency.
    c. the production of currency and minting coins.
    d. an alloying element for copper.

Answer 18

a. plating material and as an alloying element in steel.

Question 19

19. Magnesium is the lightest metal commercially
    available, with a density approximately ______
    that of aluminum.
    a. one-quarter
    b. one- third
    c. one-half
    d. two-thirds

Answer 19

d. two-thirds

Question 20

20. The high rate of strain hardening in magnesium lessens its ability to permit plastic flow at a stress concentration point. This condition is known as:
    a. hardness.
    b. notch sensitivity.
    c. ductile transition.
    d. yield elasticity.

Answer 20

b. notch sensitivity

Question 21

21. Titanium has a high corrosion resistance in all but which of the following environments?
    a. General atmosphere.
    b. Marine environment.
    c. Reducing acids.
    d. Biological environments.

Answer 21

c. Reducing acids.

Question 22

22. Titanium, like magnesium and zirconium, has a high rate of strain hardening due to its crystalline structure. Its structure is:
    a. body-centered cubic.
    b. face-centered cubic.
    c. close-packed hexagonal.
    d. face-centered hexagonal.

Answer 22

c. close-packed hexagonal.