ON STEEL RELATIVITY-REFLECTIVITY-FUNCTIONALITY

A FEW TERMS YOU NEED TO UNDERSTAND BEFORE READING FURTHER :
NOBILITY OF METALS : ABILITY TO RESIST OXIDATION AND CORROSION
GALVANIC SERIES : AN ORDER OF METALS BASED ON THEIR NOBILITY
CATHODE : POSITIVE ELECTRODE THAT ABSORBS ELECTRONS
ANODE   : NEGATIVE ELECTRODE THAT RELEASES ELECTRONS

GALVANIC ACTION IS WHEN TWO METALS ARE IN CONTACT THE ONE HIGHER IN THE GALVANIC SERIES WILL CORRODE AND TAKE THE ROLE OF ANODE. 
IT'S LIKE THE MORE NOBLE METALS ATTACK AND TAKE OUT THE ONES THAT ARE LESS NOBLE


ANODIC  [least noble]
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ALUMINIUM
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ZINC
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STEEL & IRON
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CAST IRON
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STAINLESS STEEL
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NICKEL
|
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TIN
|
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LEAD
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BRASS
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COPPER
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BRONZE
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TITANIUM
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GOLD
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CATHODIC [most noble]

CHARGE FLOWS FROM THE BOTTOM TO THE TOP OF THE SERIES
THE SERIES ALSO ESTABLISHES RELATIONSHIP BETWEEN METALS


THE CHANGE OF STATE FROM SOLID--LIQUID--GAS DEPENDS ON THE SPECIFIC GRAVITY OF THE METAL WHICH IS ALWAYS IN RELATION TO THAT OF WATER.

REFLECTIVITY : REFLECTION OF LIGHT INCIDENT ON THE SURFACE
THE MOST REFLECTIVE METAL IS STAINLESS STEEL ; SO IT DOES NOT ABSORB LIGHT RAYS AND HENCE DOES NOT CHANGE COLOR OVER A COURSE OF TIME.

OIL CANNING : THE BENDING OR INDENTATION ON STEEL FACADE MEMBERS DUE TO WIND LOAD. IT CAN BE PREVENTED BY USING BACKER RODS THAT LINE THE BACK OF THE FACADE STEEL AND STRENGTHEN AGAINST WIND FORCES.

WELDING/SOLDERING : DONE BY USING OXYGEN-ACETYLENE GAS MIXTURE.
USED FOR STRUCTURAL STEEL MEMBERS
SMALLER STEEL MEMBERS ARE WELDED USING MIG [METAL INERT GAS]
TIG [ TUNGSTEN INERT GAS]

JOINTS FOR STEEL
BOLTED
PINNED
RIVET
MECHANICALLY JOINED
MECHANICALLY FASTENED


                            STEEL
     |------------------------|------------------------|
     |                        |                        |
CARBON STEEL            STAINLESS STEEL            TOOL STEEL

HIGH CARBON                    FERRITIC                  HIGH CARBON
MEDIUM CARBON                MARTENSITIC
LOW CARBON                    AUSTENITIC
                               DUPLEX
                        PRECIPITATION HARDENING


FERRITIC: CANNOT BE HARDENED BY HEAT TREATMENT BUT CAN BE STRENGTHENED BY COLD WORKING
MARTENSITIC : HIGHLY MACHINABLE AND MAGNETIC
AUSTENITIC  : HIGHLY WELDABLE AND CORROSION RESISTANT
DUPLEX      : COMBINES FERRITIC AND AUSTENITIC STEELS AND IS TWICE AS STRONGER AS BOTH.
PRECIPITATION HARDENING : COMBINES MARTENSITIC AND AUSTENITIC STEELS.



-Veronica




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