The Science Of Welding

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The Science Of Welding

• An integrated lesson

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Topics to be Discussed

• Introduction
• What is Arc Welding?
• Why is Welding Important?
• Why Learn to Weld?
• Basic Electricity and the Science of Welding
• Electricity
• Energy Transfers
• Changes of State
• Chemical Reactions
• Welding Safety
• Careers in Welding

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Introduction

• Arc welding is a process used to join two pieces
  of metal together.
• How does it work?
• A welder creates an electric arc that melts the
  metal and filler rod to create a pool of molten
  metal that hardens to fuse the two pieces of
  metal together.

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Introduction

• Why is welding important?
• Many of the things you use need to be welded.
• Your parents car
• Power line towers
• Your school desk
• Your bicycle

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Introduction

• Why Learn to Weld?
• Welding can help build a successful career to
  earn money to buy the things you want.
• Skilled Welders are in high demand.
• Welding is challenging and high tech.

www.universalwelding.com
www.weldingschools.com
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Basic Electricity and the Science of Welding

• Voltage The electrical potential or pressure
  that causes current to flow
• Measured in Volts
• Current The movement of charged particles in a
  specific direction
• Measured in Amps
• Polarity
• DC- (Direct Current Electrode Negative)
• DC (Direct Current Electrode Positive)
• AC (Alternating Current)

DC
DC -
AC
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Basic Electricity and the Science of Welding

• The electricity flows from the power source,
  through the electrode and across the arc, through
  the base material to the work lead and back to
  the power source
• Circuit click on the link
• to learn more.
• Circuit Info.

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Basic Electricity and the Science of Welding

• Use the following links to learn how electricity
  works in a circuit
• Conductors, Insulators, and electron flow
• Current and Voltage in a Circuit
• Resistance
• Ohms Law

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Basic Electricity and the Science of Welding

• The electron flow you just learned about is what
  creates the arc in arc welding.
• This is a form of electrical energy
• How do we use that electrical energy to fuse
  metals together?

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Basic Electricity and the Science of Welding

• The energy transfers that take place in welding
• Electrical The arc created by the
• electric current is
• converted into heat
• Thermal because of the resistance of
  electron flow. The heat melts
• the metal to fuse it together.

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Basic Electricity and the Science of Welding

• Here are some places to look to learn more about
  energy and energy transfers.
• Forms of Energy
• Energy Transformations

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Basic Electricity and the Science of Welding

• Changes of State and Chemical Reactions
• During the welding process the metal changes
  states or forms.
• What are the states of matter?
• Solid
• Liquid
• Gas
• Plasma
• Click here to learn more about the changes of
  state

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Basic Electricity and the Science of Welding

• Changes of State and Chemical Reactions
• So what changes of state occur during welding?
• Initially the metal is a solid
• When the arc starts the solid is converted into a
  liquid
• Some of the liquid is converted into a gas vapor
• When the arc stops the liquid cools to form a
  solid again this is the newly formed weld joint
• Solid Liquid Solid
• (gas vapor)

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Basic Electricity and the Science of Welding

• Changes of State and Chemical Reactions
• Chemical Reactions
• During the welding process certain chemical
  reactions take place.
• Hydrogen, Oxygen, and Nitrogen can react in the
  weld puddle and cause changes in the structure of
  the weld weakening the weld.

pt.chemicalstore.com
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Welding Safety

• Because of the chemical reactions, energy
  transfers, and electricity involved in welding
  proper safety must be addressed
• Welding can be safe when sufficient measures are
  taken to protect yourself and others from
  potential hazards
• Students should read and understand the following
  before welding
• Warning Labels
• Material Safety Data Sheets (MSDS)
• Students should also be familiar with the
  following information
• Safety in Welding, Cutting, and Allied
  Processes (ANSI Z49.1)
• Lincoln Electrics Arc Welding Safety (E205)

http//www.lincolnelectric.com/knowledge/training/
weldcurriculum.asp
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Welding Safety

• Understand and follow all warning labels found
• On welding equipment
• With all consumable packaging
• Within instruction manuals

www.jpbrandit.com
http//www.lincolnelectric.com/knowledge/training/
weldcurriculum.asp
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Welding Safety

• Material Safety Data Sheets (MSDS) are
• Required by law and OSHA
• Created by the manufacturer of a product per OSHA
  guidelines
• Designed to inform users
• Shipped with every box of consumable product
• Available free online at
• www.lincolnelectric.com/products/msds/

http//www.lincolnelectric.com/knowledge/training/
weldcurriculum.asp
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Welding Safety

• MSDS outlines a products
• Identity and composition
• Potential hazards
• Safe use
• Handling information
• Manufacturer contact information

http//www.lincolnelectric.com/knowledge/training/
weldcurriculum.asp
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Welding Safety

• Protect yourself and others from potential
  hazards including
• Fumes and Gases
• Electric Shock
• Arc Rays
• Fire and Explosion Hazards
• Noise
• Hot objects

http//www.lincolnelectric.com/knowledge/training/
weldcurriculum.asp
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Welding Safety

• Fumes and gases can be hazardous to your health
• Keep your head out of the fumes
• Use enough ventilation, exhaust at the arc, or
  both, to keep fumes and gases from your breathing
  zone and the general area
• See product labeling and MSDS for ventilation and
  respirator requirements

http//www.lincolnelectric.com/knowledge/training/
weldcurriculum.asp
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Welding Safety

• Electric shock can kill
• Do not touch live electrical parts
• Primary Voltage 230, 460 volt input power
• Secondary Voltage 6 to 100 volts for welding
• Insulate yourself from work and ground
• Follow all warnings on welding equipment

http//www.lincolnelectric.com/knowledge/training/
weldcurriculum.asp
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Welding Safety

• Welding sparks can cause fires and explosions
• Sparks and spatter from the welding arc can
  spray up to 35 feet from your work
• Flammable materials should be removed from the
  welding area or shielded from sparks and spatter
• Have a fire extinguisher ready
• Inspect area for fires 30 minutes after welding

http//www.lincolnelectric.com/knowledge/training/
weldcurriculum.asp
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Welding Safety

• Welders must wear protective clothing for
• Protection from sparks, spatter and UV radiation
• Insulation from electric shock
• Protective clothing includes
• Fire-proof clothing without rolled sleeves, cuffs
  or frays
• Work boots
• Welding gloves, jackets, bibs, and fire-proof
  pants
• Welding cap, helmet and safety glasses
• Ear protection ear plugs and muffs

http//www.lincolnelectric.com/knowledge/training/
weldcurriculum.asp
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Careers in Welding

• Education
• Penn College of Technology
• Penn College Welding Video
• Welding Schools

• Careers
• American Welding Society
• Career Guide
• Welding Jobs

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Careers in Welding

• Here are some possible areas you can start a
  career in welding
• Racing
• Engineering
• Farm
• Auto Technician
• Sculpting
• Maintenance
• Iron worker
• Robotics
• Production welder
• Fabricator
• And many more

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What to learn more?

• Do you want to learn more about welding and how
  to weld? If so, go to the link below for more
  information on how to weld.
• This is to be used if your school has access
• http//www.lincolnelectric.com/knowledge/training/
  weldcubrriculum.asp

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Resources

• http//www.lincolnelectric.com/knowledge/training/
  weldcurriculum.asp
• http//www.weldinginfocenter.org/sci_tech/index.ht
  ml
• http//www.pct.edu/degreesthatwork/welding.htm
• http//www.allaboutcircuits.com/vol_1/index.html
• All photographs are cited next to photograph