Stainless Steel

Question 1

1. Which element is mainly responsible for the formation of the protective oxide on
   stainless steel?
   a) chromium
   b) nickel
   c) manganese
   d) molybdenum

Answer 1

1. a) chromium

Question 2

2. What is the minimum amount of chromium required in steel to make it a stainless
   steel?
   a) 8%
   b) 10%
   c) 15%
   d) 18%

Answer 2

2. b) 10%

Question 3

3. What is the most outstanding characteristic of stainless steel?
   a) thermal conductivity
   b) electrical conductivity
   c) modulus of elasticity
   d) corrosion resistance

Answer 3

3. d) corrosion resistance

Question 4

4. Generally, stainless steel has a:
   a) low coefficient of thermal expansion and a low thermal conductivity.
   b) low coefficient of thermal expansion and a high thermal conductivity.
   c) high coefficient of thermal expansion and a low thermal conductivity.
   d) high coefficient of thermal expansion and a high thermal conductivity.

Answer 4

4. c) high coefficient of thermal expansion and a low thermal conductivity.

Question 5

5. Which type of stainless steel contains the most nickel?
   a) austenitic
   b) ferritic
   c) martensitic
   d) stainless steel does not contain nickel

Answer 5

5. a) austenitic

Question 6

6. Which type of stainless steel is non-magnetic?
   a) austenitic
   b) ferritic
   c) martensitic
   d) all stainless steels are non-magnetic

Answer 6

6. a) austenitic

Question 7

7. Which type of stainless steel has a face-centred cubic (fcc) structure like that of iron at high temperatures?
   a) austenitic
   b) ferritic
   c) martensitic
   d) stainless steels do not have an fcc structure

Answer 7

7. a) austenitic

Question 8

8. Which type of stainless steel has a body-centred cubic (bcc) structure like that of iron at room temperature and cannot be hardened by heat treatment?
   a) austenitic
   b) ferritic
   c) martensitic
   d) all stainless steels have a bcc structure

Answer 8

8. b) ferritic

Question 9

9. Which 400 series stainless steel can be heat-treated to a wide range of hardness and
   strength levels?
   a) austenitic
   b) ferritic
   c) martensitic
   d) 400 series are not stainless steels

Answer 9

9. c) martensitic

Question 10

10. Which two alloying elements in martensitic stainless steels are responsible for its high hardenability?
    a) chromium and nickel
    b) carbon and copper
    c) carbon and chromium
    d) carbon and columbium

Answer 10

10. c) carbon and chromium

Question 11

11. Which type of stainless steel is magnetic?
    a) 201
    b) 308
    c) 316
    d) 410

Answer 11

11. d) 410

Question 12

12. AISI 200 and 300 series stainless steels are:
    a) martensitic.
    b) ferritic.
    c) austenitic.
    d) not weldable.

Answer 12

12. c) austenitic.

Question 13

13. Which series of chromium steels (4% to 6% chromium) are not classified as stainless
    steels?
    a) 200 series
    b) 300 series
    c) 400 series
    d) 500 series

Answer 13

13. d) 500 series

Question 14

14. Which two series of stainless steels have an austenitic grain structure?
    a) 100 and 200
    b) 200 and 300
    c) 300 and 400
    d) 400 and 500

Answer 14

14. b) 200 and 300

Question 15

15. Which series of stainless steel can be either ferritic or martensitic?
    a) 200 series
    b) 300 series
    c) 400 series
    d) 500 series

Answer 15

15. c) 400 series

Question 16

16. What is the result of carbide precipitation?
    a) increased corrosion resistance
    b) loss of corrosion resistance
    c) increased magnetic properties
    d) an increase in ductility

Answer 16

16. b) loss of corrosion resistance

Question 17

17. What is the maximum carbon content level in an ELC grade stainless steel?
    a) 0.03%
    b) 0.05%
    c) 0.08%
    d) 0.10%

Answer 17

17. a) 0.03%

Question 18

18. When welding austenitic stainless steel, the interpass temperature should not be
    higher than:
    a) 149°C (300°F).
    b) 204°C (400°F).
    c) 316°C (600°F).
    d) 899°C (1650°F).

Answer 18

18. c) 316°C (600°F).

Question 19

19. Which two elements have been added as stabilizers to AISI stainless steels type 347
    and 321?
    a) carbon and titanium
    b) columbium and titanium
    c) carbon and columbium
    d) titanium and chromium

Answer 19

19. b) columbium and titanium

Question 20

20. One method used to prevent carbide precipitation is to:
    a) use high amperage settings and large electrodes.
    b) keep the interpass temperature above 316°C (600°F).
    c) use weave techniques instead of stringer beads.
    d) maintain a short arc length so as not to burn out the chromium.

Answer 20

20. d) maintain a short arc length so as not to burn out the chromium.

Question 21

21. What is the significance of a stainless steel SMAW electrode with the suffix 15?
    a) It can only be used with DCRP only.
    b) It can be used with AC or DCRP.
    c) It can only be used with AC.
    d) It must be used in the flat position only.

Answer 21

21. a) It can only be used with DCRP only.

Question 22

22. Which statement is true with respect to an E308-16 electrode?
    a) It has a lime-type coating for use with DCEP.
    b) It has a titania-type coating for use with AC.
    c) It has a titania-type coating for use with DCEN.
    d) The electrode may be used in the flat position only.

Answer 22

22. b) It has a titania-type coating for use with AC.

Question 23

23. Which stainless steel electrode contains the highest chromium content?
    a) E308
    b) E310
    c) E347
    d) E410

Answer 23

23. b) E310

Question 24

24. What is the significance of the L in the filler metal designation ER309L?
    a) light gauge
    b) low chromium
    c) low carbon
    d) low columbium

Answer 24

24. c) low carbon

Question 25

25. What is the main reason for keeping stainless steel electrodes and welding rods dry?
    a) to be able to weld in all positions
    b) to eliminate porosity and cracking
    c) to increase the rate of metal transfer
    d) to increase the shelf life of the electrodes

Answer 25

25. b) to eliminate porosity and cracking

Question 26

26. What precaution should be taken when using stainless steel electrodes that have been
    rebaked at high temperatures?

a) Use AC current only to control undercut and arc blow.
b) Use an external shielding, as the electrodes do not generate a protective slag.
c) Use insulated gloves, as the electrodes may be too hot to handle.
d) Handle the electrodes carefully, as the flux may crumble and fall off

Answer 26

26. d) Handle the electrodes carefully, as the flux may crumble and fall off.

Question 27

27. Under what conditions should stainless steel filler metals be stored after they are
    removed from their sealed container?
    a) in electrode holding ovens
    b) dry in a closed container
    c) in a humid location
    d) cold in a dry environment

Answer 27

27. a) in electrode holding ovens

Question 28

28. How should stainless steel sheet stock be stored?
    a) in racks with all the other steel sheets
    b) outside because it will not rust
    c) separately, supported by heavy steel stands
    d) separately, supported by wooden blocking

Answer 28

28. d) separately, supported by wooden blocking

Question 29

29. When fabricating with stainless steel, a good practice is to use:
    a) hardened steel jigs and vice grips.
    b) stainless steel brushes.
    c) a carbon pencil to mark the dimensions.
    d) a general purpose grinding disc with a very fine grit.

Answer 29

29. b) stainless steel brushes.

Question 30

30. What consideration must be taken when welding stainless steel to help ensure a high quality welded joint?
    a) Do not grind after air carbon arc gouging.
    b) Use a welding grade carbon dioxide shielding gas.
    c) Remove moisture by heating with dry air.
    d) Clean the joint before, but not after welding.

Answer 30

30. c) Remove moisture by heating with dry air