Metals Flashcards
Alloy:
a combination of pure metals to give greater strength or resistance to corrosion
Ferrous Alloy:
alloys that contain a lot of iron (e.g.: stainless steel, galvanized iron)
rolling
process of passing metal through rollers to produce the needed shape
- can be done while metal is hot or cold
- hot rolling eliminates flaws in the metal
- cold rolling inceases metal’s strength and elastic limit, but decreases ductility
Non Ferrous Alloys:
doesn’t contain much iron (e.g.: aluminum, copper, zinc)
Cast Iron:
hard brittle alloy of iron and 2.1 - 4% carbon that can be readily cast in a
mold, use for pipes, plumbing fixtures, hardware, castings, etc. (Crystal Place made of it)
Wrought Iron:
iron that has been purified by beating it repeatedly with a hammer, used
for ornamental work, grilles, pipes, and outdoor furniture (Eiffel Tower made of it)
Steel:
any range of alloys of iron and carbon that contain less than 2% carbon, the most
widely used structural metal in construction, used for framing, concrete, rebar, lathing,
conduit, pipes, fixtures, connectors like nails, bolts, and pins.
Aluminum:
Light weight metal with good thermal/electrical conductivity and resistance
to corrosion, used for lightweight framing, railings, grills, siding, curtain walls, doors/
windows, flashings, roofing, hardware, etc
Galvanic Corrosion:
an electrochemical process where one metal corrodes preferentially to another when they both are in electrical contact and immersed in an electrolyte (which is a liquid or gel that contains ions and can be decomposed by electrolysis)
Purpose of Galvanizing:
When metal is going to be used in an environment where corrosion is likely, it is often galvanized so that it will be able to withstand the conditions.
Galvanizing:
coating iron or steel with a protective layer of zinc by immersing it in a molten bath.
Anodizing:
process of coating aluminum with a protective oxide layer by an electrolytic process
galvanic series
zinc
glavanized steel
aluminum
steel and iron
stainless steel
lead
tine
copper alloys (brass, bronze)
copper
-listed in order of sesceptibility to corrosion; the farther apart the metals are, the more likely corrosion will occur when the metals are in direct contact
As carbon is added to steel…
strength increases but ductility deacreases
Copper:
Metal that resists corrosion, electrical and thermal activity, used for electrical
work, water pipes, roofing/flashing, and mesh
Brass:
metal that resists corrosion, used for finish hardware, plumbing, HVAC
components and fittings
Lead:
Metal that resists corrosion and is workable, but also toxic, heavy, soft, and weak,
used for foundations, rough hardware, roofing and flashing
Zinc:
Metal used for roof coverings, flashings, and protective coatings for steel
Monel:
Metal used for roofing, flashing, countertops, sinks
Bessemer Process:
steelmaking procedure where carbon, silicon, and other impurities
are removed from iron to make steel.
Basic Oxygen Process:
steelmaking procedure where a hollow, water-cooled lance is
lowered into a container of molten iron/recycled steel scrap and a stream of pure oxygen
is blown in at high pressure from the lance to burn off the excess carbon/impurities.
Light Gauge Steel:
steel that is cold rolled and lighter than .018”
Bulb Tees:
a steel reinforcing member used when constructing pre-stressed, poured
gypsum deck. When the gypsum is poured, it surrounds the Bulb-Tee.
terneplate
an alloy of 75% lead and 25% tin used to plate steel for roofing
