rk7-2 task 1

Question 1

Which of the following has high hardenability when welded?

a. low carbon steels
b. austenite steels
c. low alloy steels
d. high carbon steels

Answer 1

d. high carbon steels

Question 2

molybdenum is used as an alloy for hardenability, high-temperature resistance and for

a. strength
b. austenite stabilization
c. machinability
d. ductility

Answer 2

a. strength

Question 3

high strength low alloy Steels have an advantageous combination of high-strength and

1. red hardness
2. oxidation resistance
3. ductility
4. reactivity

Answer 3

c. ductility

Question 4

the high strength low alloy Steels with an AR designation are used where ____________ is required.

1. a low melting point
2. high hardness
3. high strength
4. flexibility

Answer 4

b. high hardness

Question 5

all stainless Steels are a combination of iron carbon and

1. nickel
2. chromium
3. copper
4. molybdenum

Answer 5

b. chromium

Question 6

the most outstanding characteristic of stainless steel is its

1. corrosion sesistance
2. electrical conductivity
3. elastisity
4. thermal conductivity

Answer 6

a. corrosion resistance

Question 7

which of the following alloying elements in stainless Steels is responsible for an austentic grain structure at room temperature?

1. chromium
2. cobalt
3. molybdenum
4. nickel

Answer 7

d. nickel

Question 8

which two alloying elements in martensitic stainless steels are responsible for their high hardenability?

1. carbon and nickel
2. carbon and copper
3. carbon and chromium
4. carbon and molybdenum

Answer 8

c. carbon and chromium

Question 9

which of the AISI series are austenitic in grain structure?

1. 100 and 200 series
2. 200 and 300 series
3. 300 and 400 series
4. 400 and 500 series

Answer 9

b. 200 and 300 series

Question 10

which of the stainless Steels does not undergo transformation to austenite upon heating?

1. molybdenum
2. ferritic
3. martensitic
4. manganese

Answer 10

b. ferritic

Question 11

in order to prevent cracking in ferritic stainless steels

1. carbide precipitation mustbe carefully controlled
2. high copper electods must be used
3. higher het inputs are required
4. heat input must be carefully controlled

Answer 11

d. heat input must be carefully controlled

Question 12

Which two elements have been added as stabilizing elements to the AISI stainless Steels 321 and 347?

1. carbon and copper
2. titanium and boron
3. tantalum and columbium
4. titanium and columbium

Answer 12

d. titanium and columbium

Question 13

which of the stainless steel series suffer from carbide precipitation?

1. 100 series
2. 300 series
3. 400 series
4. 500 series

Answer 13

b. 300 series

Question 14

at what temperature range is carbide precipitation most likely to occur?

1. 149°C to 400°C (300°F to 725°F)
2. 400°C to 500°C (752°F to 932°F)
3. 427°C to 816°C (800°F to 1500°F)
4. 850°C to 1160°C 1562°F to 2120°F)

Answer 14

c. 427°C to 816°C (800°F to 1500°F)

Question 15

what is the result of carbide precipitation?

1. decreased hardness
2. loss of corrosion resistance
3. increased magnetic properties
4. increased ductility

Answer 15

b. loss of corrosion resistance