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DAH 9/20/97 1 TABLE of CONTENTS TABLE of CONTENTS BASIC METALLURGY BASIC METALLURGY SOLID WIRES SOLID WIRES COVERED ELECTRODES COVERED ELECTRODES CORED WIRES CORED WIRES

Metallurgical facts

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Page 1: Metallurgical facts

DAH 9/20/97 1

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