6.1 - Ferrous Metals

Question 1

When talking about ferrous materials what is the base material.

Answer 1

Iron

Question 2

How is iron extracted from iron ore.

Answer 2

By mixing it with coke and limestone.

Question 3

Why does cast iron have limited use in the aviation industry.

Answer 3

Low strength to weight ratio and Brittleness.

Question 4

Carbon contents of steel.

Answer 4

Low = 0.1 - 0.3 %
Medium = 0.3 - 0.5 %
High = 0.5 - 1.05 %

Question 5

What % does hardness and tensile strength stop increasing at.

Answer 5

85%

Question 6

Carbon allows what in steel to occur.

Answer 6

Heat treatment.

Question 7

Sulphur in steel does what.

Answer 7

Decreases ductility and weld ability with increasing content. But increases machine ability

Question 8

Manganese in steel does what.

Answer 8

Contributes to strength and hardness but not as much as carbon.

Decreases ductility and weld ability.

Question 9

Increasing manganese content in steel decreases what.

Answer 9

Ductility and weld ability

Question 10

Silicon does what to steel.

Answer 10

Increases rolled strength and hardness

Question 11

Phosphorus in steel does what.

Answer 11

Increases strength, hardness and corrosion resistance but decreases ductility.

Question 12

Nickel does what to steel.

Answer 12

Increases the harden ability and impact strength.

Question 13

Chromium does what to steel

Answer 13

Increase corrosion resistance, oxidation resistance, Hardenability and improve high-temperature strength. Frequently used in conjunction with toughening elements like nickel.

Question 14

Molybdenum does what to steel.

Answer 14

Increases harden ability

Question 15

Titanium in steel does what

Answer 15

Increases toughness

Question 16

SAE stands for

Answer 16

Society of automotive engineers

Question 17

ASI stands for

Answer 17

American institute of steel and iron

Question 18

Annealing does what to steel.

Answer 18

Softens and relieves internal stresses.

Question 19

What is the process of annealing for steel.

Answer 19

Heating the steel to 50 degrees F above is upper crit limit and soaking it at that temperature. Then it’s called slowly in a furnace or bath of hot sand.

This will make the steel very soft and ductile.

Question 20

What ferrous material can be hardened by heat treatment.

Answer 20

Cast iron

Question 21

The maximum hardness of steel depends entirely on what added compound.

Answer 21

Carbon.

Question 22

Carbon steel can be softened by.

Answer 22

Annealing.

Question 23

Steel is too hard and brittle so what process decreases this so steel can be used.

Answer 23

Tempering

Question 24

Tempering does what to steel.

Answer 24

Decreases hardness and increases ductility and toughness.

Question 25

What is normalising.

Answer 25

The process of heating steel to relieve stresses caused during forging, welding and machineing.

Question 26

What’s the normalising process.

Answer 26

Heat the steel to 100 degrees F above upper crit limit then soak at that temp for a prescribed time then allow to cool at room temp.

Question 27

What determines the rate of quenching.

Answer 27

The medium in which the metal is being quenched.

Question 28

Ferrite is.

Answer 28

The name given to pure iron that allow for .02% carbon to be absorbed into it.

Question 29

How much carbon can ferrite iron absorb.

Answer 29

0.02%

Question 30

Austenite can absorb how much carbon.

Answer 30

Up to 2%

Question 31

Cementite iron has what characteristics

Answer 31

Hard and brittle

Question 32

Cementite is iron with what carbon content

Answer 32

Greater than 2%

Question 33

CRES stands for.

Answer 33

Corrosion resistant steel

Question 34

CRES has what characteristics.(4)

Answer 34

Corrosion resistant, strength, toughness and resistance to high temperatures.

Question 35

For the CRES classification chart what steel type is represented by (200 and 300), (400)

Answer 35

200 and 300 is austenitic | 400 is ferritic and martensitic

Question 36

Most widely used CRES is.

Answer 36

In the 300 series and called 18-8

Question 37

Austenitic steels are what alloys

Answer 37

Chromium-nickel and chromium-Nickel-manganese alloys.

Question 38

Austenitic can be hardened by

Answer 38

Cold working, heat treatment only anneals them.

Question 39

Austenitic steel is what in an annealed state and what can it be after being cold worked.

Answer 39

After annealing the steel is non magnetic but after being cold worked can be slightly magnetic.

Question 40

Titanium helps to stop what in steel.

Answer 40

Intergranular corrosion

Question 41

Steel classification is in what format.

Answer 41

First 2 digits refer to the primary alloying element and the last 2 the the percentage of carbon contained in the alloy.