EXAM 4

Question 1

_____________ iron is extremely hard cast iron.

Answer 1

White

Question 2

_________________________ are graphitizers.

Answer 2

Silicon, Nickel, Copper

Question 3

______________ irons are gray or ductile irons containing alloying elements that are designed to improve high-temperature strength and oxidation resistance.

Answer 3

Heat-resistant

Question 4

____________ iron is the most widely used cast iron.

Answer 4

Gray

Question 5

Carbon and _____________ are the principal alloying elements in cast irons.

Answer 5

Silicon

Question 6

___________ stainless steels are the most weldable stainless steels.

Answer 6

Austenitic

Question 7

When __% Cr or more is added to the iron or steel, they become stainless.

Answer 7

12%

Question 8

__________________ is the principal element influencing the corrosion resistance of stainless steels.

Answer 8

Chromium

Question 9

The majority of austenitic stainless steels belong to the AISI _________ series.

Answer 9

300

Question 10

A ________________ film is a film on the outer surface layer of a metal that has superior corrosion resistance.

Answer 10

passive surface

Question 11

Free-machining coppers are modified copper containing _________________.

Answer 11

sulfer, tellurium, and lead

Question 12

Welding difficulties of copper alloys are associated with their___________________.

Answer 12

high thermal conductivity, high fluidity, and hot shortness

Question 13

Brass is a wrought alloy of copper and _________.

Answer 13

zinc

Question 14

____________ coppers are purified, commercially pure coppers.

Answer 14

tough pitch

Question 15

Explain how copper alloys are designated.

Answer 15

Copper is designated according to composition and thermal properties

Question 16

Annealed or cast commercially pure aluminum has _______ of the tensile strength of structural steel.

Answer 16

1/5

Question 17

_______________ is the selective attack of one metal when it is electrically coupled to another metal in a conductive environment

Answer 17

galvanic corrosion

Question 18

The _________ series comprises aluminum-silicon alloys.

Answer 18

4XX.X

Question 19

A ________________ designation is a letter than indicates the final condition of cold-worked (H) or heat-treated (T) material.

Answer 19

temper

Question 20

List the desirable properties of aluminum.

Answer 20

• low density
• high specific strength
• high electrical and thermal conductivity
• good corrosion resistance

Question 21

Grade __ is the most widely used titanium alloy.

Answer 21

5

Question 22

Forming processes for titanium alloys are hampered by ____________________.

Answer 22

notch sensitivity, poor shrinkability, and galling

Question 23

The primary difference between the various grades of commercially pure titanium is the ____________ content.

Answer 23

interstitial element

Question 24

The crystal structure of pure titanium at room temperature is __________.

Answer 24

CPH

Question 25

_____________ behavior is the spontaneous ignition of a metal when scratched or struck.

Answer 25

Pyrophoric