Metals Flashcards
1
Q
Measuring behaviour of metals
A
- Stress and strain
- On a graph= Y = stress and X = strain
- Increase of stress = increase of strain
2
Q
Yield Point
A
- Point object doesn’t revert to original state due to stress (aka yield strength)
- Height on y (stress/sigma) = stress point
- If goes past yield point becomes elastoplastic
3
Q
Proof Stress
A
- Used when cannot find actual yield point
- 0.1% on x axis cutting through curve of stress/strain line
- When max point on graph is reached = tensile strength (when necking happens)
4
Q
Slip
A
- Deformation from dislocation motion
- Slip from one dislocation is tiny
5
Q
Affectors of metal behaviour
A
- Grain structure
- Atom arrangement within grains
- (Smaller grains = stronger metals)
6
Q
Alloys
A
- Solid solution made of 2 metals
- Substitutional solid solution: Atoms of another element can replace existing atoms in host if similar grain size
7
Q
Interstitial Solid Solution
A
2 elements with different atoms that can fit within spaces of one another (interstices)
8
Q
Steel Production and Processing
A
- Carbon removed from iron to become cast iron
- Increased carbon content = increased strength
9
Q
Steel Production 1 - Ironmaking
A
- Smelting iron ores
- Collect raw material (iron ore and coal)
- Put in blast furnace
- Makes pig iron
10
Q
Steel Production 2 - Steelmaking
A
- Remove impurities from metal (using pure oxygen) to create crude steel
- Impurities lower strength and durability once hardened
- If impurities are not removed the material is unusable
- Molten iron is poured into a converter furnace
11
Q
Steel Production 3 - Rolling
A
- Pressure forming crude steel into finished products
12
Q
Iron
A
- Pure iron = 0% carbon - ferrite
- In iron with 0.2% carbon ferrite gaps have lines in. Lines are cementite (carbon and iron) and the gaps are ferrite
13
Q
Annealing
A
- Method of changing shape of steel
- Heating to 60% of melting temperature causing atoms to rearrange themselves allowing new grain formation
