metallurgical facts
TRANSCRIPT
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TABLE of CONTENTSTABLE of CONTENTS
BASIC METALLURGYBASIC METALLURGY
SOLID WIRESSOLID WIRES
COVERED ELECTRODESCOVERED ELECTRODES
CORED WIRESCORED WIRES
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BASIC METALLURGYBASIC METALLURGY
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TERMINOLOGYTERMINOLOGY
Carbon Steel - Carbon Steel - Alloy of iron and carbonAlloy of iron and carbonLow carbon steel - Up to .15% carbonLow carbon steel - Up to .15% carbon
Mild carbon steel - .15% to .29% carbonMild carbon steel - .15% to .29% carbon
Medium carbon steel - .30% to .59% carbonMedium carbon steel - .30% to .59% carbon
High carbon steel - .60% to 1.7% carbonHigh carbon steel - .60% to 1.7% carbon
Mild Steel - Mild Steel - Same as aboveSame as above
Low Alloy Steel - Low Alloy Steel - 1-1/2% to 5% alloy content1-1/2% to 5% alloy content
High Alloy Steel - High Alloy Steel - Contains more than 10% alloyContains more than 10% alloy
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TERMINOLOGYTERMINOLOGY
Ferrous - Ferrous - Contains some ironContains some iron
Non-Ferrous - Non-Ferrous - No iron content, ex. (Al and Cu) No iron content, ex. (Al and Cu)
Preheat - Preheat - Heating of part before welding - Slows Heating of part before welding - Slows weld metal cooling rate weld metal cooling rate
Interpass Temperature - Interpass Temperature - The temperature range heldThe temperature range held during welding - (minimum during welding - (minimum and maximum) and maximum)
As Welded - As Welded - (AW) - No postweld heat treatment(AW) - No postweld heat treatment
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TERMINOLOGYTERMINOLOGY
Postweld Heat Treatment - Postweld Heat Treatment - Heating the part after Heating the part after welding welding
Stress Relieved - Stress Relieved - (SR) - Heated to a specific(SR) - Heated to a specific temperature and time after temperature and time after welding, ex. (1150 welding, ex. (11500 0 F for 1 hr./in.)F for 1 hr./in.)
Deoxidizers - Deoxidizers - Elements that have an affinity for Elements that have an affinity for oxygen - Helps to clean and purify oxygen - Helps to clean and purify weld metal weld metal
Flux - Flux - Cleans the weld metal - Floats impurities to Cleans the weld metal - Floats impurities to the surface in the form of slag the surface in the form of slag
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ALLOYING ELEMENTSALLOYING ELEMENTS
Carbon (C) - Carbon (C) - Increases strength and hardnessIncreases strength and hardness
Manganese (Mn) - Manganese (Mn) - Deoxidizer; also increases Deoxidizer; also increases strength and hardness strength and hardness
Silicon (Si) - Silicon (Si) - Deoxidizer and increases puddle Deoxidizer and increases puddle fluidity fluidity
Aluminum (Al) - Aluminum (Al) - Deoxidizer and grain refinerDeoxidizer and grain refiner
Titanium (Ti) - Titanium (Ti) - Deoxidizer and grain refinerDeoxidizer and grain refiner
Zirconium (Zr) - Zirconium (Zr) - Deoxidizer and grain refinerDeoxidizer and grain refiner
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ALLOYING ELEMENTSALLOYING ELEMENTS Molybdenum (Mo) - Molybdenum (Mo) - Increases strength and depth Increases strength and depth
of hardeningof hardening
Chromium (Cr) - Chromium (Cr) - Increases corrosion resistance Increases corrosion resistance and hardening and hardening
Nickel (Ni) - Nickel (Ni) - Increases toughness and corrosion Increases toughness and corrosion resistance resistance
Copper (Cu) - Copper (Cu) - Improves corrosion resistanceImproves corrosion resistance
Sulfur (S) - Sulfur (S) - Causes brittleness but improves Causes brittleness but improves machinability machinability
Phosphorus (P) - Phosphorus (P) - Greatly reduces ductilityGreatly reduces ductility and toughness and toughness
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WELDABILITYWELDABILITY
Weld metal soundnessWeld metal soundness Porosity free weldsPorosity free welds Deoxidizer level - Mn, Si, Al, Ti, and ZrDeoxidizer level - Mn, Si, Al, Ti, and Zr
Weld puddle fluidity, bead shape, and edge Weld puddle fluidity, bead shape, and edge wettingwetting
Mn and Si increase puddle fluidityMn and Si increase puddle fluidity Al, Ti, and Zr make the puddle sluggishAl, Ti, and Zr make the puddle sluggish
Spatter tendencySpatter tendency Alloying ingredients affect spatterAlloying ingredients affect spatter Shielding gas selection - Ar vs. COShielding gas selection - Ar vs. CO22
Optimize welding parameters to minimizeOptimize welding parameters to minimize spatterspatter
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MECHANICAL PROPERTIESMECHANICAL PROPERTIES
Ultimate Tensile Strength (UTS)Ultimate Tensile Strength (UTS) The maximum stress the weldment withstood The maximum stress the weldment withstood
without breaking - (psi)without breaking - (psi)
Yield Strength (YTS)Yield Strength (YTS) The stress point where permanent deformation The stress point where permanent deformation
occurs - (psi)occurs - (psi)
Charpy V-Notch Impact Test - (CVN)Charpy V-Notch Impact Test - (CVN) Measures energy required to break specimen - Measures energy required to break specimen -
(ft.-lbs.)(ft.-lbs.) Tested at a specific temperature ( Tested at a specific temperature ( 00F)F) Will always appear as ( Will always appear as ( xx ft.-lbs. @ ft.-lbs. @ yy 00F)F)
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MECHANICAL PROPERTIESMECHANICAL PROPERTIES
Mechanical Properties
Impact Toughness
Charpy Impact Test Machine
Charpy V-NotchSpecimen
Fractures Cracks Deforms
Energyin ft/lbs
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MECHANICAL TEST SPECIMENSMECHANICAL TEST SPECIMENS
TENSILE TEST
BEND TEST
CHARPY TEST
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Tensile Testing EquipmentTensile Testing Equipment
Stress/Strain Recorder
Specimen Holders
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Impact Testing EquipmentImpact Testing Equipment
Swinging Pendulum
Cryogenic Holding ChamberSpecimen Mount
Recorder