6.1 - Ferrous Metals Flashcards
When talking about ferrous materials what is the base material.
Iron
How is iron extracted from iron ore.
By mixing it with coke and limestone.
Why does cast iron have limited use in the aviation industry.
Low strength to weight ratio and Brittleness.
Carbon contents of steel.
Low = 0.1 - 0.3 % Medium = 0.3 - 0.5 % High = 0.5 - 1.05 %
What % does hardness and tensile strength stop increasing at.
85%
Carbon allows what in steel to occur.
Heat treatment.
Sulphur in steel does what.
Decreases ductility and weld ability with increasing content. But increases machine ability
Manganese in steel does what.
Contributes to strength and hardness but not as much as carbon.
Decreases ductility and weld ability.
Increasing manganese content in steel decreases what.
Ductility and weld ability
Silicon does what to steel.
Increases rolled strength and hardness
Phosphorus in steel does what.
Increases strength, hardness and corrosion resistance but decreases ductility.
Nickel does what to steel.
Increases the harden ability and impact strength.
Chromium does what to steel
Increase corrosion resistance, oxidation resistance, Hardenability and improve high-temperature strength. Frequently used in conjunction with toughening elements like nickel.
Molybdenum does what to steel.
Increases harden ability
Titanium in steel does what
Increases toughness
SAE stands for
Society of automotive engineers
ASI stands for
American institute of steel and iron
Annealing does what to steel.
Softens and relieves internal stresses.
What is the process of annealing for steel.
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.
What ferrous material can be hardened by heat treatment.
Cast iron
The maximum hardness of steel depends entirely on what added compound.
Carbon.
Carbon steel can be softened by.
Annealing.
Steel is too hard and brittle so what process decreases this so steel can be used.
Tempering
Tempering does what to steel.
Decreases hardness and increases ductility and toughness.
What is normalising.
The process of heating steel to relieve stresses caused during forging, welding and machineing.
What’s the normalising process.
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.
What determines the rate of quenching.
The medium in which the metal is being quenched.
Ferrite is.
The name given to pure iron that allow for .02% carbon to be absorbed into it.
How much carbon can ferrite iron absorb.
0.02%
Austenite can absorb how much carbon.
Up to 2%
Cementite iron has what characteristics
Hard and brittle
Cementite is iron with what carbon content
Greater than 2%
CRES stands for.
Corrosion resistant steel
CRES has what characteristics.(4)
Corrosion resistant, strength, toughness and resistance to high temperatures.
For the CRES classification chart what steel type is represented by (200 and 300), (400)
200 and 300 is austenitic
400 is ferritic and martensitic
Most widely used CRES is.
In the 300 series and called 18-8
Austenitic steels are what alloys
Chromium-nickel and chromium-Nickel-manganese alloys.
Austenitic can be hardened by
Cold working, heat treatment only anneals them.
Austenitic steel is what in an annealed state and what can it be after being cold worked.
After annealing the steel is non magnetic but after being cold worked can be slightly magnetic.
Titanium helps to stop what in steel.
Intergranular corrosion
Steel classification is in what format.
First 2 digits refer to the primary alloying element and the last 2 the the percentage of carbon contained in the alloy.
