Materials EGR Quiz 4

Ferrous

ex. steel, stainless steel, cast iron

Non-Ferrous

ex. aluminum, magnesium, copper, exotic metals

Metal Alloys

ferrous and non-ferrous

Steel Designation

1010: 10 = plain carbon, 10 = carbon contents in tenths of wt%

4340: 43 = nickel chrome moly, 40 = 0.4 wt%

Low Carbon

< 0.25 wt% C ex. automobile panels very ductile when annealed, machinable, not heat treatable, strain harden

Medium Carbon

0\.25 < wt% C < 0.6

ex. crankshaft, bolts

good combination of strength and ductility, heat treatable in small cross section or with addition of other alloys

High Carbon

>0.6 wt% C

ex. blades, tooling

very strong, low ductility, heat treatable, form carbides

Stainless Steels

'stainless' means passivating, forms a protective oxide coating almost immediately when exposed to the atmosphere, you can stain stainless steel

Types of Stainless Steel

Ferrite, Austenite, Martensite

Ferrite

cheap, simple, machinable

ex. automotive exhaust

Austenite

most corrosion resistant, non-magnetic

ex. silverware

Martensite

heat treatable

ex. cutlery, rifle barrels

Types of Iron

gray, white, malleable, ductile, CGI (compacted graphite iron)

Gray Iron

cheap, most prevalent, silicon added

ex. cook ware

White Iron

very hard, very wear resistant, not machinable (cracks)

ex. rollers in rolling mill

Malleable Iron

strong, yet ductile, produced by reheating white iron

ex. transmission housing

Ductile Iron (modular)

more ductile, easier to machine than gray, vibration resistant, magnesium added

ex. gears

CGI Iron

fancy, high strength, high temp

ex. diesel engine blocks

Types of Non-Ferrous Alloys

copper, copper alloys, aluminum, titanium, magnesium, exotic alloys

Cast Iron

Cementite (Fe3c)

Ferrite (Fe3(alpha))+Graphite(c)

Copper Alloys

Brass (copper and zinc) ex. ammunition

Bronze (copper and tin) ex. clutch disks

Copper-Nickel (Brickle) ex. heat exchanger components

Copper-Beryllium (Bopper) ex. springs

Wrought Copper Alloys

ductile enough to be formed, bending, rolling, drawing

Cast Copper Alloys

Only ductile enough to be cast

Aluminum

high strength to weight/density, high modulus to weight/density, corrosion resistance through passivation, thermal/electrical conductivity

Aging

natural: wait at room temperature

artificial: heat to a temperature for a time to encourage diffusion

Temper Designation

O - annealed, highest ductility

F - as fabricated

T1 - cooled from an hot forming process and naturally aged

T3 - solution heat treated, cold worked, naturally aged

T6 - solution heat treated, artificially aged

Titatium

strong, light, high-melting temperature, heat treatable

ex. rocket engines

Refractory Metals

Niobium (Nb), Molybdenum (Mo), Tantalum (Ta), Tungsten (W)

high melting temps and low reactivity

ex. crucible