6.1 Ferrous materials✅(3) Flashcards
(64 cards)
1
Q
What does ‘ferrous’ refer to?
A
- metals and alloys
2
Q
An alloy containing iron as its main ingredient is called what
A
ferrous metal (and is magnetic)
3
Q
What are the most common ferrous metal in aircraft structures
A
- Steel
- an alloy (with controlled amount of carbon and other materials)
4
Q
What are the properties of pure iron?
A
- ductile
- soft
- easily formed
5
Q
How is Iron oxide formed
A
- Iron reacts with oxygen
6
Q
Advantage of cast iron
A
- low strength to weight ratio
7
Q
What material is the most common man-made materials in the world
A
steel
8
Q
What is the base material of steel
A
iron
9
Q
How do you make steel
A
pig iron/cast iron is re-melted in a special furnace
10
Q
what is Tensile strength?
A
- Ability of a metal to withstand stress in tension
11
Q
What is compressive strength?
A
- Ability of a metal to withstand ‘pressing’ or ‘squeezing’
12
Q
What is torsional strength?
A
- ability to resist rotational shear
13
Q
What is Flexural strength?
A
- bending strength of a metal
14
Q
What is impact strength?
A
- Measures ability of a metal to resist shock
15
Q
What is hardness?
A
- ability to resist cutting, penetration, or abrasion
16
Q
What is malleability?
A
- ability to be bent, formed, or shaped without cracking
17
Q
What is brittleness?
A
- Materials tendency to break or shatter when exposed to stress
18
Q
What is conductivity?
A
- Property that enables a metal to carry heat or electricity
19
Q
What is thermal expansion?
A
- Property of a metal to expand when heated, and shrink when it is cooled
20
Q
What is elasticity?
A
- Metals tendency to return to its original shape after normal stretching/bending
21
Q
What is toughness?
A
- materials ability to resist tearing or breaking when bent or stretched
22
Q
What is fusibility?
A
- ability of metal to be joined by heating and melting
23
Q
What is the most common alloying element found in steel
A
carbon
24
Q
Higher carbon content decreases the malleability and weldability of steel (T or F)
A
T
25
What is the carbon content for low carbon steel?
0.1%-0.3%
26
What is the carbon content for medium carbon steel?
0.3%-0.5%
27
What is the carbon content for high carbon steel?
0.5%-1.05%
28
What does sulphur cause steel to be when rolled or forged
Sulphur causes steel to be brittle
29
What does silicon act as when alloyed with steel
hardener
30
When using silicon in small quantities, what does it improve
ductility
31
What does nickel do when added to steel
- adds strength and hardness
- increases yield strength
32
What is the most widely used alloying elements used for aircraft structural steel?
molybdenum
33
What does chromium do when alloyed with steel
- increase strength and hardness
- improve wear and corrosion resistance
34
Molybdenum steels are extremely wear resistant and possesses a great deal of fatigue strength (T or F)
T
35
What occurs when vanadium is combined with chromium ?
- produces strong, tough, ductile steel alloy
36
What are most wrenches and ball bearings made out of?
Chrome-vanadium steel
37
Tungsten has an extremely high melting point (T or F)
T
38
Stainless steel can be classified into 3 groups which are?
- Austenitic
- Ferritic
- Martensitic
39
What are Austenitic stainless steel referred as
- referred as 200 and 300 series stainless steels
40
What are Ferritic stainless steel part of
- part of the 400 series of stainless alloys
41
Ferritic stainless steel have what as their major alloying element
-chromium
42
Ferritic stainless steels are magnetic (T or F)
T
43
What is the major alloying element with martensitic?
- Chromium (in the range of 11%-17%)
44
What does the first digit for classification of steel identify?
the principal alloying element
45
What does the last 2 digits digit for classification of steel identify?
average carbon content in %
46
What type of stainless steel is used for cookware/food equipment?
Austenitic
47
What type of stainless steel is used for kitchenware/exhaust/furnaces?
Ferritic
48
What type of stainless steel is used for cutlery/surgical instruments/scissors/industrial blades?
Martensitic
49
Steel is hardened by raising its temperature to above the upper critical temperature (T or F)?
T
50
What is the critical temperature?
- temperature at which a phase change occurs in a metal, during heating or cooling
51
What is quenching?
-rapidly cool a material after heating in water/oil
52
What is annealing?
- softens steel and relieves internal stresses
53
Why can annealed parts not be used on aircraft
due to soft and ductile nature
54
Explain the annealing process
Heating a steel to 10*c above upper critical limit and heat soaking it at this temperature
55
What is normalising?
- involves heating steel to 38*c above its upper critical limit and soaking for prescribed time
56
When normalising, how is the steel cooled?
at room temperature
57
What is tempering
- method used to decrease hardness
- increasing ductility, toughness
58
What is the least accurate method of estimating temperature?
- observing colour of the material being heated
59
What is direct hardening?
-surface heated rapidly to high temperatures
- then cooled rapidly (generally using water)
60
Direct hardening consists of flame or induction hardening process (T or F)?
T
61
How is the steel heated in induction hardening?
by an induction coil
62
When the steel is heated to the necessary temperature (induction hardening) what occurs next?
- current switched off
- immediately quenched by jets of water
63
What are the 2 methods to case harden
- Carburising
- Nitriding
64
When do you usually carry out normalising
- after welding
