Materials

Question 1

Carbon steel

Answer 1

Low Carbon steel: 0.05% to 0.2%, Easy to weld, general equipment
Medium Carbon Steel: 0.3% to 0.5%, balances ductility and strength, good wear resistance, used for large parts, forging and automotive
High carbon steel: 0.6% to 1.0%, very strong, used for springs, shafts, tools, high strength wires
Ultra high carbon steel: 1.25% to 2%, can be tempered to high hardness, used for special purpose like knives and punches.

Question 2

Hardening

Answer 2

Basic Hardening Process:
-Heat the metal to a cherry red
-Rapid cool (quench) the material in water or oil.
-Part may be brittle so temper by bringing up to a moderate temperature, blue or straw colour and quenching

Question 3

Hot rolled steel (Black)

Answer 3

Most common form of steel
Black due to oxide scale left after hot rolling
Moderate dimension accuracy
Relatively easy to cut, machine, weld and bend

Question 4

I Beam

Answer 4

Web is in the middle, Flange is the outside part, excellent bending strength

Question 5

Channel

Answer 5

Looks like a C, poor for Buckling and twisting

Question 6

Silver Steel

Answer 6

NOT MADE FROM SILVER, Bright and almost mirror finish, very high strength steel, high carbon content, used in tool rooms, makes drills, taps, engravers, punches etc

Question 7

High Speed Steel

Answer 7

Most drills, taps and dies, custom ground lathe tools, very hard and good wear resistance, retain hardness at high temperatures, cannot be cut or shaped with conventional cutting tools

Question 8

Hard Chrome Bar

Answer 8

Steel bar with hard chrome plating, precision ground and polished surface, use for hydraulic and pneumatic rams, non-corrosive

Question 9

CopperStainless Steel

Answer 9

Non-Corrosive, pots, pans, hospitals, chemical plants, breweries and hand rails

Question 10

Aluminium

Answer 10

Extruded (NOT SEAM WELDED), moderate corrosion resistance, not as strong as steel, less dense than steel, more difficult to weld and more expensive then steel

Question 11

Brass

Answer 11

Copper-Zinc alloy, tubes are extruded not seam welded, moderate corrosion resistance, difficult to weld, not as strong as steel, more expensive than steel and aluminium. Used in plumbing fittings, taps, door knobs and decorative things