Lesson 11 - Steel Reinforcement Flashcards
IT is an element, compound, or alloy that is a good conductor of both electricity and heat
Metal crystal structure and specific metal properties are determined by metallic
bonding - force, holding together the atoms of a it
Other specific features are: luster or shine of their surface (when polished), their malleability (ability to be hammered) and ductility (ability to be drawn). These properties are also associated with the bonding and presence of free electrons in the crystal lattice.
Metal
DIVISION OF METALS
- FERROUS METALS
- Those metal that contain iron as the base metal.
- NON FERROUS METALS
- Metals that do not have iron as their base metal
- atomic number 26
- most widely used of all metals as a base metal in steel and cast ____
Iron
the intermediate product of smelting iron ore with a high-carbon fuel such as
coke, usually with limestone as a flux
Pig iron
is derived from pig iron
Cast Iron
Types of Cast Iron
White Cast Iron
Grey Cast Iron
is named after its white surface when fractured, due to its carbide
impurities which allow cracks to pass straight through.
White Cast Iron
is named after its grey fractured surface, which occurs because the
graphitic flakes deflect a passing crack and initiate countless new cracks as the
material breaks.
Grey Cast Iron
- iron alloy with a very low carbon content, in comparison to steel, and has
fibrous inclusions (slag) - tough, malleable, ductile and easily welded
WROUGHT IRON
an alloy that consists mostly of iron and has a carbon content between
0.2% and 2.1% by mass
Carbon is the most common alloying material for iron, but various other alloying elements are used, such as manganese, chromium, vanadium, molybdenum, tungsten, etc.
Steel
Also called Inox Steel, is a steel alloy with a minimum of 10.5 or 11%
chromium content by mass. It does not corrode, rust, or stain with water as
ordinary steel does.
Stainless Steel
- Forms: castings, sheet, plate, bar, rod, channel and forgings.
- Lighter than most metals, do not rust or corrode, can be forged, machined and
welded easily
Aluminum
- Reddish metal, very ductile and malleable. High electrical and heat conductivity. Can be forged, cast and cold worked, can be welded. Very common in electrical industry made into wire and conductors. Typical products are sheets, bushings, wire, bearings.
Copper
an alloy of copper and zinc. Has low melting point and high heat
conductivity. Good machinability and can be welded.
Brass
an alloy of copper and tin. Has high strength, rust or corrosion
resistant, good machinability and can be welded.
Bronze
Used in coating steel, and alloying element, in the form of foil. Can be die cast,
cold worked, machined and soldered but cannot be welded.
Tin
Used mainly in the manufacturing of electrical equipment (telephone cables and storage batteries) Low strength with heavy weight, can be casted, cold worked, welded and machined
Lead
Used in making alloys for both ferrous and non-ferrous metals. Can be readily
welded by gas or arc methods can be machined, forged cast and formed easily.
Nickel
The controlled heating and cooling operations used to bring about the desired change in the properties of metal. Its purpose is to improve the structural and physical properties of metal.
HEAT TREATMENT OF METALS
HEAT TREATMENT OF METALS
- HEATING
- SOAKING (QUENCHING)
- COOLING
HEATING
a. MECHANICAL MIXTURE
b. SOLID SOLUTION
can be compared to concrete (sand and
gravel are visible and held in place by the grout) elements and compounds are
held together by a matrix of base metal.
a. MECHANICAL MIXTURE
- two or more metals are absorbed, one into the other and form a solution.
b. SOLID SOLUTION
Once a metal part has been heated to the temperature at which desired changes
in its structure will take place, it must remain at that temperature until the entire part has been evenly heated throughout.
SOAKING (QUENCHING)
The structure may change from one chemical composition to another, it may stay the same or may revert to its original form. It is significant in order to
increase the metals hardness, toughness. ductility, tensile strength.
Cooling
STRUCTURAL CONNECTIONS
- RIVETING
- WELDING
- BOLT
holes are punched or drilled through the members to be connected and a steel
___ will be inserted through the holes
RIVETING
A connection is neat, and the metal is stronger than the metal
being connected.
WELDING
manufactured with heads on one end and thread on the other, washer may be
used.
Bolt
IMPORTANT PROPERTIES OF STEEL
TENSILE STRENGTH
DUCTILITY
MALLEABILITY
The ability of a metal to resist being pulled apart by opposing forces acting in a straight line.
TENSILE STRENGTH
The ability of a metal to be drawn or stretched permanently without rupture or
fracture.
DUCTILITY
The ability of metal to return to be hammered, rolled or pressed into various
shapes without rupture or fracture.
MALLEABILITY
