Metallurgy Flashcards
Learn about lattice structures, alloys and heat control. (118 cards)
1
Q
The science that explains the properties, behavior, and internal structure of metals is called what?
A
Metallurgy
2
Q
Electrical and thermal conductivity, hardness, strength, ductility and toughness are all:
A
Metallurgical properties
3
Q
The ability to withstand impact is:
A
Toughness
4
Q
Fracture toughness results will often be expressed in terms of:
A
Breaking energy
5
Q
As hardness is increased, _______ is decreased.
A
Ductility
6
Q
As temperature increases during tempering, what property decreases?
A
Hardness
7
Q
Rockwell, Vickers, Knoop and Brinell are tests used to determine what metallurgical property?
A
Hardness
8
Q
The ability to deform without failing is:
A
Ductility
9
Q
As temperature decreases, which property also decreases?
A
Ductility
10
Q
Aluminum, copper and soft steels are high in what metallurgical property?
A
Ductility
11
Q
Ductility can be expressed in terms of:
A
Percent elongation and/or reduction of area
12
Q
The absence of ductility cannot be measured itself, but the metallurgical property is called:
A
Brittleness
13
Q
The tendency to deform very little before failing suddenly, describes:
A
Brittleness
14
Q
As a materials hardness increases, does its strength increase?
A
Yes
15
Q
The ability to resist crushing is:
A
Compressive strength
16
Q
The ability to withstand indentation is:
A
Hardness
17
Q
Files and drill bits are high in what metallurgical property?
A
Hardness
18
Q
Impact wrenches, jack hammers and connecting rods are high in what matellurgical property?
A
Toughness
19
Q
Lifting tools, come-a-longs and bearing pullers are high in what metallurgical property?
A
Tensile strength
20
Q
The ability to withstand a static load is:
A
Strength
21
Q
The ability of a material to return to its original form after stress is removed is called:
A
Elasticity
22
Q
The ability of a material to be cyclically loaded without failing is called:
A
Fatigue strength
23
Q
Deformation caused by stress is called what?
A
Strain
24
Q
A material performs elastically until it passes its yield point. After its yield point has been reached, the material performs:
A
Plastically
25
The property expressed in terms of endurance limit is:
Fatigue strength
26
The point on a stress-strain curve where the material changes from elastic to plastic is called its:
Yield point
27
When atoms or molecules group together in a neat, orderly formation, they form what?
Grains (crystals)
28
Larger or smaller, which grain size exhibits greater strength?
Smaller
29
Are course grains weaker than small grains?
Yes
30
What is the lower transformation temperature of steel?
1,333 F
31
A graph showing the phases and temperatures at which alloys exist is called what?
Phase diagram
32
What does PWHT stand for?
Post Weld Heat Treatment
33
Which type of PWHT (post weld heat treatment) results in the softest carbon steel?
Annealing
34
The type of PWHT (post weld heat treatment) where the material is heated above the lower transformation temperature, held for a certain amount of time, and slow cooled in a furnace is:
Annealing
35
Which type of PWHT (post weld heat treatment) softens the metal more than normalizing?
Annealing
36
The type of PWHT (post weld heat treatment) where the material is heated above the lower transformation temperature, held for a certain amount of time, and cooled in still air is:
Normalizing
37
The type of PWHT (post weld heat treatment) where the material is heated to less than the lower transformation temperature and slow cooled:
Stress relieving
38
Which types of PHWT (post weld heat treatment) involve heating the metal to a temperature between 1500 - 1800 F?
Normalizing and annealing
39
The PWHT (post weld heat treatment) that follows quenching and restores some of the metal's ductility is:
Tempering
40
Brine, water or oil may be used for what PWHT (post weld heat treatment) technique?
Quenching
41
The primary goal of PWHT (post weld heat treatment) is to relieve what?
Residual stress
42
What technique for controlling distortion does not help reduce residual stress?
External restraint
43
What two factors determine if a material requires preheat?
Carbon equivalent and thickness
44
Use of preheat results in:
A slower cooling rate and wider HAZ (heat affected zone)
45
The capacity of a material to be welded into a specific, suitably designed structure performing satisfactorily in the intended service is called:
Weldability
46
Carbon equivalent is used to determine which property?
Weldability
47
Low-carbon steel has a carbon content of _____ % or less.
0.30%
48
Medium-carbon steels have a carbon content between 0.30% and \_\_\_\_\_\_%.
0.55%
49
A pure substance composed of a single material is called what?
An element
50
Steels that are primarily made of iron are called:
Ferrous
51
A material made up of two or more elements, at least one of which is a metal, is called what?
An alloy
52
Which alloying element has the greatest effect on steel?
Carbon
53
Which alloying element gives carbon steel the best corrosion resistance?
Chrome
54
What two ways can atoms of an alloy be incorporated into the original metal structure?
Substitutionally or interstitially
55
The type of alloying where atoms of the alloy take the places of original atoms in a metals structure is known as:
Substitutional alloying
56
The type of alloying where atoms of the alloy are dispersed between the original structure is known as:
Interstitial alloying
57
Steels alloyed with carbon and only a low percentage of silicon and manganese are known as:
Plain carbon steels
58
The melting point of steel is approximately:
2,500 F
59
Time-temperature-transformation (TTT) charts show what?
Grain growth
60
Carburizing, nitriding and localized heating are types of what?
Surface hardening
61
The surface-hardening technique that impregnates the outer surface of steel with carbon is called:
Carburizing
62
In the four digit numbering system for steels, what do the last two numbers designate?
Percentage of carbon
63
In the four digit numbering system for steels, what do the first two numbers designate?
Major alloying elements
64
For a steel designated 4140, what is its carbon content?
0.40%
65
The process of removing dissolved oxygen from molten metal is called:
Deoxidation
66
The energy applied to the work-piece during welding is called:
Heat input
67
The calculation for heat input is:
(Amps x Volts x 60) / Travel Speed = J/in
68
Using a smaller diameter electrode and increasing travel speed will have what effect on heat input?
Heat input will decrease
69
An increase in amperage and voltage will have what effect on heat input?
Heat input will increase
70
The unit for measuring work or heat energy is called a:
Joule
71
Expansion and shrinkage during welding causes what two stresses?
Residual stress and distortion
72
Relieving residual stress in a weld by using impact blows is called:
Peening
73
Can stress relieving be accomplished by mechanical means?
Yes
74
Vibratory stress relief is another term for what mechanical stress relief?
Peening
75
The portion of base metal which has not been melted, but whose mechanical properties or microstructure has been altered by the heat of welding is called:
Heat-affected zone (HAZ)
76
HAZ stands for:
Heat affected zone
77
All matter contains heat down to absolute zero. What temperature is absolute zero?
-460 F
78
Protons, neutrons and electrons form what?
Atoms
79
What is the smallest part of an element?
An atom
80
Atoms changing position while a material is in its solid state is called:
Diffusion
81
Atoms combine to form what?
Molecules
82
Carbon steel exists in what unit cell arrangement at room temperature?
BCC
body centered cubic
83
Which microstructure is the hardest?
Martensite
84
The unit cell arrangement with the closest arrangement of atoms is:
HCP
hexagonal closed packed
85
The three types of unit cell arrangement for metals are:
BCC, FCC, and HCP
body centered cubic, face centered cubic, and hexagonal closed packed
86
Which crystal lattice structure is shown here?
BCC
body centered cubic
87
Which crystal lattice structure is shown here?
FCC
face centered cubic
88
Which crystal lattice structure is shown here?
HCP
hexagonal close packed
89
Which microstructure is shown here, characterized by a fine, needle-like apprearance?
Martensite
90
Rapid cooling of carbon steel from the austenitic range will result in the formation of:
Martensite
91
Slow cooling of steel helps produce a soft, ductile microstructure which has a lamellar appearance when viewed under a microscope. This structure is:
Pearlite
92
Which microstructure is shown here, characterized by a lamellar appearance?
Pearlite
93
Which microstructure is shown here, the result of combining two other microstructures?
Ferrite-pearlite
94
Which microstructure is shown here, characterized by being mostly white with only small carbon deposits in black.
Ferrite
95
The maximum temperature that a metal reaches during welding is called:
Interpass temperature
96
Organic compounds like water, oil and grease all contain what element that can be detrimental to welding?
Hydrogen
97
Which alloying element acts as a deoxidizer?
Silicon
98
Which alloying element improves corrosion resistance?
Chrome
99
Which alloying element increases toughness and ductility?
Nickel
100
The three states of matter are:
Liquid, solid and gas
101
A wider HAZ (heat affected zone), a slower cooling rate and smaller grain size are all benefits of what?
Preheat
102
Metals like aluminum, brass and copper that do not have iron as their base are called what?
Non-ferrous
103
A steel designated 4130 has a carbon content of what?
0.30%
104
Quenching a material from temperatures above the lower transformation temperature will result in what microstructure?
Martensite
105
What crystal lattice structure can be described as a cube with an atom at each corner and a single atom in the center of the cube?
BCC
body centered cubic
106
What lattice structure can be described as a cube with an atom at each corner and an atom in the center of each face of the cube?
FCC
face centered cubic
107
Does molten steel have a crystal lattice structure?
No
108
What happens to matter as it is heated?
It expands
109
Stainless steels have a minimum chromium content of:
12%
110
Ferritic, martensitic, austenitic and precipitation hardened are all types of:
Stainless steels
111
"300" series stainless steels is what grade?
Austenitic
112
"400" series stainless steels are what grade?
Martensitic
113
Which state of matter has the least amount of energy?
Solid
114
The ability of a material to absorb energy is:
Toughness
115
Metals that are strongly attracted by a magnet are called what?
Ferromagnetic
116
What kind of metal is classified 6061-T6?
Aluminum
117
What does 'HAZ' mean?
Heat Affected Zone
118
What is the HAZ?
The base metal adjacent to the weld that was heated to a high temperature but not melted
