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Worksheets6.1 Materiais aeronáuticos — Ferrosos
Total questions: 98
Worksheet time: 3hrs 16mins
Name
Class
Date
1.
What is the typical chromium content in stainless steel used in aircraft?
a)
0.05
b)
10-13%
c)
0.25
2.
Which alloying element increases corrosion resistance in steel?
a)
Carbon
b)
Chromium
c)
Sulphur
3.
How is high-strength steel identified during spark testing?
a)
Long branching sparks
b)
Bright white sparks with forking
c)
Short dull red sparks
4.
What carbon content defines medium carbon steel?
a)
Below 0.3%
b)
0.3–0.8%
c)
Above 0.8%
5.
What is a key feature of austenitic stainless steel?
a)
Magnetic
b)
Heat-treatable
c)
Non-magnetic
6.
Which steel is commonly used for aircraft engine components?
a)
AISI 304
b)
AISI 4130
c)
AISI 1010
7.
Which of these steel types can be hardened by heat treatment?
a)
Low carbon steel
b)
Austenitic stainless steel
c)
Martensitic stainless steel
8.
What is the main purpose of tempering steel?
a)
Harden surface
b)
Reduce brittleness
c)
Increase carbon content
9.
Which heat treatment gives the toughest steel microstructure?
a)
Normalising
b)
Annealing
c)
Tempering
10.
What is case hardening?
a)
Softening the core
b)
Harden only the surface
c)
Tempering after quenching
11.
Which process is used to harden only the surface of a ferrous material?
a)
Case hardening
b)
Tempering
c)
Annealing
12.
What is the recommended inspection for surface defects in ferrous welds?
a)
Penetrant Testing
b)
Magnetic Particle Testing
c)
Ultrasonic Testing
13.
What is a key purpose of annealing steel?
a)
Increase brittleness
b)
Relieve stress and soften metal
c)
Increase surface hardness
14.
Which steel is preferred for good weldability?
a)
High carbon steel
b)
Medium carbon steel
c)
Low carbon steel
15.
Which test measures resistance to indentation?
a)
Tensile Test
b)
Impact Test
c)
Hardness Test
16.
What material structure is usually formed by normalising?
a)
Austenite
b)
Pearlite
c)
Martensite
17.
How is fatigue resistance typically improved in steel?
a)
Annealing
b)
Shot peening
c)
Cold working
18.
Which inspection method is best for thick ferrous components?
a)
Ultrasonic Testing
b)
Magnetic Particle Testing
c)
Visual Inspection
19.
What is the main cause of brittleness in high-carbon steel?
a)
High temperature
b)
High carbon content
c)
Low temperature
20.
What is one drawback of using Brinell hardness test?
a)
Too slow
b)
Leaves large indentations
c)
Only tests surface
21.
What is typically used as a quenchant in steel hardening?
a)
Air
b)
Water
c)
Ammonia
22.
Which of these is a non-destructive test?
a)
Fracture test
b)
Spark test
c)
Magnetic particle inspection
23.
What does carburising do to low-carbon steel?
a)
Makes it ductile
b)
Adds surface hardness
c)
Increases tensile strength
24.
Which tool is used to identify ferrous materials?
a)
Hardness tester
b)
Spark tester
c)
Load cell
25.
What characterizes a martensitic steel structure?
a)
Soft and ductile
b)
Hard and brittle
c)
Elastic and tough
26.
Which steel treatment enhances internal toughness and removes stress?
a)
Case hardening
b)
Tempering
c)
Normalising
27.
Which inspection method relies on sound wave reflection?
a)
Eddy Current
b)
Ultrasonic
c)
Penetrant
28.
Which alloying element gives strength and ductility to steel?
a)
Manganese
b)
Chromium
c)
Nickel
29.
What is the outcome of cold working a steel component?
a)
Increases ductility
b)
Causes work hardening
c)
Makes it magnetic
30.
Which method is best for inspecting welds in thick sections?
a)
Ultrasonic testing
b)
Visual inspection
c)
Penetrant testing
31.
What is the effect of shot peening on fatigue life?
a)
No change
b)
Decreases
c)
Increases
32.
Why is austenitic stainless steel non-magnetic?
a)
Low carbon
b)
High chromium
c)
Austenite structure
33.
What does the term "tempering" mean in steel processing?
a)
Surface hardening
b)
Stress relief after hardening
c)
Carbon addition
34.
Which material property is evaluated by Charpy test?
a)
Hardness
b)
Impact strength
c)
Tensile strength
35.
What visual clue identifies high carbon steel in a spark test?
a)
Few short sparks
b)
Many long bursting sparks
c)
White unbranched lines
36.
What is the function of copper during carburising?
a)
Increase hardness
b)
Prevent case hardening
c)
Protect core from oxidation
37.
Which element increases creep resistance in high-temp steels?
a)
Chromium
b)
Molybdenum
c)
Nickel
38.
What happens to pearlite when quenched rapidly?
a)
Transforms into martensite
b)
Remains unchanged
c)
Becomes ferrite
39.
What inspection detects only surface-breaking defects?
a)
Eddy Current
b)
Penetrant Testing
c)
Ultrasonic
40.
Which structure is strongest but most brittle?
a)
Martensite
b)
Pearlite
c)
Ferrite
41.
Why is Inconel suitable for aircraft?
a)
Light weight
b)
High creep strength and oxidation resistance
c)
Cheap and available
42.
What kind of fracture surface indicates ductile material?
a)
Shiny and smooth
b)
Irregular with dimples
c)
Flat and grainy
43.
Which heat treatment enhances machinability?
a)
Hardening
b)
Normalising
c)
Annealing
44.
What is the typical spark pattern of low carbon steel?
a)
Short dull red
b)
Long bright sparks with few bursts
c)
Bright and branching
45.
Which method identifies steel types quickly?
a)
Load test
b)
Ultrasonic test
c)
Spark test
46.
Which property is vital in aircraft structures?
a)
Brittleness
b)
Hardness
c)
Fatigue resistance
47.
Which process causes stress relief in ferrous metals?
a)
Quenching
b)
Annealing
c)
Case hardening
48.
What is normalising used for?
a)
To soften surface
b)
Refine grain and stress relief
c)
To harden outer layer
49.
Which structure provides best toughness in steel?
a)
Martensite
b)
Bainite
c)
Ferrite-Pearlite mix
50.
What is the result of rapid cooling in steel?
a)
Formation of austenite
b)
Formation of martensite
c)
Retained pearlite
51.
What process improves both ductility and grain structure in alloy steel?
a)
Tempering
b)
Annealing
c)
Normalising
52.
What heat treatment process is used to soften hardened steel?
a)
Carburising
b)
Tempering
c)
Annealing
53.
Which steel is best for carburising?
a)
Low carbon steel
b)
High carbon steel
c)
Austenitic steel
54.
What visual cue indicates low carbon steel in a spark test?
a)
Long and dull sparks
b)
Bright and branching sparks
c)
No sparks
55.
Which process increases surface hardness while keeping the core ductile?
a)
Tempering
b)
Case hardening
c)
Normalising
56.
What alloying element in steel improves creep resistance?
a)
Manganese
b)
Molybdenum
c)
Sulphur
57.
What defines high-carbon steel?
a)
Less than 0.3% carbon
b)
0.3–0.8% carbon
c)
Above 0.8% carbon
58.
Which element is responsible for improving toughness and fatigue life?
a)
Nickel
b)
Chromium
c)
Vanadium
59.
What is the microstructure formed by slow cooling steel?
a)
Martensite
b)
Pearlite
c)
Bainite
60.
Which heat treatment refines grain and improves strength?
a)
Tempering
b)
Annealing
c)
Normalising
61.
Which element makes steel more resistant to corrosion?
a)
Nitrogen
b)
Chromium
c)
Phosphorus
62.
Why is martensitic steel used in aircraft?
a)
Magnetic and corrosion-resistant
b)
Heat-treatable and strong
c)
Flexible and lightweight
63.
What does tempering do after hardening?
a)
Makes steel brittle
b)
Relieves stress and reduces brittleness
c)
Adds carbon
64.
What property is tested using spark testing?
a)
Hardness
b)
Steel composition
c)
Magnetism
65.
What does AISI 4130 steel offer for aircraft use?
a)
High cost
b)
Good weldability and strength
c)
Low corrosion resistance
66.
Which stainless steel grade is austenitic and widely used?
a)
304
b)
410
c)
420
67.
What element makes maraging steel unique?
a)
High carbon
b)
High manganese
c)
High nickel
68.
What does quenching achieve in steel treatment?
a)
Removes surface defects
b)
Converts austenite to martensite
c)
Improves ductility
69.
Why is austenitic steel not heat-treatable?
a)
High ductility
b)
Austenite is stable at room temperature
c)
Contains low carbon
70.
Which property is improved by normalising steel?
a)
Tensile strength
b)
Electrical conductivity
c)
Oxidation resistance
71.
What happens to steel during annealing?
a)
Becomes brittle
b)
Softens and stress-relieves
c)
Increases carbon content
72.
Which is not a feature of austenitic stainless steel?
a)
Non-magnetic
b)
Corrosion-resistant
c)
Heat-hardenable
73.
Why is sulphur undesirable in aircraft steels?
a)
Makes it harder
b)
Makes it brittle
c)
Improves ductility
74.
Which structure provides highest strength in steel?
a)
Ferrite
b)
Martensite
c)
Pearlite
75.
Which phase forms during rapid quenching?
a)
Ferrite
b)
Bainite
c)
Martensite
76.
What is the main feature of AISI 4340 steel?
a)
Low carbon
b)
Excellent toughness and wear resistance
c)
High corrosion resistance
77.
Which steel type is preferred for high-strength aircraft parts?
a)
Austenitic stainless
b)
Low carbon
c)
Alloy steel (e.g. AISI 4140)
78.
What does carburising do to steel?
a)
Removes carbon
b)
Adds surface hardness
c)
Reduces weight
79.
Which element prevents grain growth in alloy steels?
a)
Chromium
b)
Vanadium
c)
Nickel
80.
What structure results from over-tempering?
a)
Hard martensite
b)
Soft and weak structure
c)
Normalised pearlite
81.
Which heat treatment hardens only the steel surface?
a)
Annealing
b)
Case hardening
c)
Tempering
82.
Which feature distinguishes maraging steel?
a)
High ductility
b)
Age-hardening via precipitation
c)
Carburising ability
83.
Which property is critical in aircraft steel selection?
a)
Color
b)
Hardness-to-weight ratio
c)
Elasticity
84.
Which element increases oxidation resistance?
a)
Chromium
b)
Nickel
c)
Vanadium
85.
Which element enhances strength without reducing ductility?
a)
Nickel
b)
Carbon
c)
Sulphur
86.
What is the spark pattern of AISI 1020?
a)
Short bursts
b)
Long dull red
c)
White with forks
87.
Which alloy is corrosion-resistant but not heat treatable?
a)
AISI 304
b)
AISI 4340
c)
AISI 4130
88.
What is the purpose of using high-nickel steels in aircraft?
a)
Lower cost
b)
High strength and stability
c)
Easy machinability
89.
Which heat treatment produces fine pearlite structure?
a)
Quenching
b)
Normalising
c)
Annealing
90.
Which test measures steel’s toughness?
a)
Charpy
b)
Rockwell
c)
Brinell
91.
Which process can relieve residual stress after welding?
a)
Tempering
b)
Annealing
c)
Case hardening
92.
What structure forms from air-cooled steel?
a)
Bainite
b)
Ferrite
c)
Pearlite
93.
Which property is NOT associated with high carbon steels?
a)
Brittleness
b)
High weldability
c)
Hardness
94.
Which method hardens steel without altering its core?
a)
Tempering
b)
Case hardening
c)
Annealing
95.
Why is low carbon steel used in structural parts?
a)
Low cost
b)
Good strength and weldability
c)
High hardness
96.
What does stress relieving prevent in aircraft parts?
a)
Cracking under load
b)
Rusting
c)
Flexing
97.
Which property makes AISI 4140 suitable for landing gear?
a)
Low weight
b)
High toughness and fatigue strength
c)
High elasticity
98.
What does Brinell testing evaluate?
a)
Surface finish
b)
Hardness
c)
Elasticity
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