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THE EFFECTS OF
ELEMENTS ALLOYED IN CARBON, ALLOY AND STAINLESS STEELS CAN BE EITHER BENEFICIAL
OR DETRIMENTAL DEPENDING ON BOTH THE QUANTITY OF THE ELEMENT OR ITS COMPANION
ELEMENTS. |
|
ALUMINUM (Al) |
PROMOTES FINE GRAINS IN LOW-CARBON STEELS WHILE RETARDING THE SUSCEPTIBILITY
TO AGE HARDENING. CONTRIBUTES TO THE PRECIPITATION HARDENING QUALITIES OF
SOME STAINLESS STEELS. |
|
CARBON (C) |
THE PRINCIPAL ALLOYING ELEMENT FOR
THE STRENGTHENING AND HARDENING OF CARBON AND ALLOY STEELS, USUALLY WITH A
SACRIFICE IN DUCTILITY. |
|
CHROMIUM (Ch) |
INCREASES HARDENABILITY AND WEAR RESISTANCE
OF ALLOY STEELS. IMPROVES RESISTANCE TO CHEMICAL CORROSION AND SCALING IN
AIR AT ELEVATED TEMPERATURES. |
|
COBALT (C) |
INCREASES STRENGTH AND HARDNESS AND
PERMITS HIGHER QUENCHING TEMPERATURES. IT ALSO INTENSIFIES THE INDIVIDUAL
EFFECTS OF OTHER MAJOR ELEMENTS IN A MORE COMPLEX STEEL. |
|
COLUMBIUM (Cb) + TANTALUM
(Ta): |
USED IN COMBINATION.
STABILIZERS FOR STAINLESS STEELS. |
|
MANGANESE (Mn) |
A SULFIDE-FORMER THAT DECREASES THE TENDENCY TO CRACK DURING THE
HOT-WORKING OPERATIONS. HARDENS CARBON AND ALLOY STEELS AND PROMOTES
WELDABILITY. |
|
MOLYBDENUM (Mo) |
INCREASES STRENGTH, HARDNESS, HARDENABILITY, AND TOUGHNESS AS WELL AS
CREEP RESISTANCE AND STRENGTH AT ELEVATED TEMPERATURES. IT IMPROVES
MACHINABILITY AND RESISTANCE TO CORROSION AND INTENSIFIES THE EFFECT OF
OTHER ALLOYING ELEMENTS |
|
NICKEL (N) |
INCREASES STRENGTH AND HARDNESS
WITHOUT SACRIFICING DUCTILITY AND TOUGHNESS. ALSO INCREASES RESISTANCE TO
CORROSION AND SCALING AT ELEVATED TEMPERATURES. |
|
PHOSPHORUS (P) |
INCREASES STRENGTH AND HARDNESS AND IMPROVES MACHINABILITY. HOWEVER IT
ADDS MARKED BRITTLENESS OR COLD-SHORTNESS TO STEEL. |
|
SELENIUM (Se) |
IMPROVES MACHINABILITY.
|
|
SILICON (Si) |
A DEOXIDIZER USED FOR "KILLING" STEELS RESULTING IN FINER GRAINS AND
IMPROVED DUCTILITY. IMPROVES SCALING RESISTANCE OF STAINLESS STEELS.
IMPARTS SPECIAL MAGNETIC PROPERTIES TO IRON BASE ALLOYS. SILICON ALSO
STRENGTHENS LOW ALLOY STEELS. |
|
SULFUR (Su) |
FORMS LOCALIZED EMBRITTLED STRIATIONS THAT IMPROVE MACHINABILTY WHILE
DECREASING DUCTILITY AND IMPACT STRENGTH, PARTICULARLY IN THE TRANSVERSE
DIRECTION. DECREASES WELDABILITY. |
|
TITANIUM (Ti) |
A CARBIDE-FORMER, IT STABILIZES
STAINLESS STEELS TO PROMOTE WELDABILITY WITHOUT SACRIFICING CORROSION
RESISTANCE. REFINES GRAINS IN CARBON AND ALLOY STEELS. |
|
TUNGSTEN (W) |
INCREASES STRENGTH, HARDNESS, AND
TOUGHNESS. TUNGSTEN STEELS HAVE SUPERIOR HOT-WORKING AND GREATER CUTTING
EFFICIENCY AT ELEVATED TEMPERATURES. |
|
VANADIUM (V)
|
FORMS FINE GRAINS AND CONTRIBUTES TO THE DEEP-HARDENING PROPERTIES OF
ALLOY STEELS.
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