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Arc Welding Basics. Unit Topics. Topics included in this overview are: Introduction What is Arc Welding? Why is Welding Important? Why Learn to Weld? Careers in Welding The American Welding Society (AWS) Welding Safety Basic Electricity Welding Fundamentals Welding Certification.
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Unit Topics • Topics included in this overview are: • Introduction • What is Arc Welding? • Why is Welding Important? • Why Learn to Weld? • Careers in Welding • The American Welding Society (AWS) • Welding Safety • Basic Electricity • Welding Fundamentals • Welding Certification
Objectives • Upon successful completion of this unit of study, you will be able to … • Identify definitions and terminology associated with welding • Demonstrate safe working habits in the welding environment • Name the parts and types of welds and weld joints • Interpret basic welding symbol information • Identify opportunities available to welders
What is Arc Welding? • Arc welding is most commonly used to join two pieces of metal • The welder creates an electric arc that melts the base metals and filler metal (consumable) together so that they all fuse into one solid piece of metal Final weld after several beads are made Steel Pipe – Tack Welded Root Pass or “Stringer Bead”
Why is Welding Important? • Many things around us are welded … • Pipelines that bring fresh water • Towers that carry electricity to houses • Cars and buses that take people where they need to go
Why Learn to Weld? • Welding is so HOT …. it’s COOL! • Welding can help build a successful career so you can get the things you want in life • Skilled welders are in demand – people use things that are welded everyday! • Welding can be fun and safe • It is challenging and high-tech
Basic Steps of Arc Welding • Prepare the base materials: remove paint and rust • Choose the right welding process • Choose the right filler material • Assess and comply with safety requirements • Use proper welding techniques and be sure to protect the molten puddle from contaminants in the air • Inspect the weld
The American Welding Society • Who is the AWS? • American Welding Society • It is a non-profit organization whose membership includes: • Individuals • Students • Companies • What do they do? • Their purpose is to: • Advance the science, technology, and application of welding and allied processes including: joining, brazing, soldering, cutting, and thermal spray • Standardize classification of electrode and base material codes • Standardize process procedures • Provide welding certification
Engineering Racing Industrial Sales Farm Repair and Fabrication Production Welding Military Teaching Maintenance Robotics Ironworker/ Skilled Trades Auto Technician Artist Metal Sculpting Owning Your Own Business Careers in Welding Job opportunities in welding are changing … Welding can be valuable as a job skillor as afull-time job For more information on welding careers, please see the e-learning introduction
How Much Money Can You Make? • Recent statistics show that some welding jobs pay $25.00 per hour - If you worked five days a week for one year, how much money would you make? • 83% of people with welding jobs were offered medical benefits - Higher than any other work sector except government For more information on welding statistics, please log on to www.bls.gov
Let’s explore some career possibilities in welding Please log on to a computer Working with a team member, research the websites to the right and explore information about welding careers In 60 minutes, be prepared to answer the following questions: What careers in welding interest you the most? How can welding be high tech? How much money can be made annually in this chosen career field? Where can you get a job in welding and what are the basic requirements? What are some job advancement opportunities available in the welding industry? America's Job Bank (http://www.ajb.dni.us) Classifieds Employment (http://www.classifieds2000.com) Yahoo! Careers (http://careers.yahoo.com/) MONSTER.COM (http://www.monster.com)(http://nccer.monster.com) CareerBuilder (http://www.careerbuilder.com) Application Activity
Arc Welding Safety • 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 Electric’s ‘Arc Welding Safety’ (E205)
Warning Labels • Understand and follow all warning labels found: • On welding equipment • With all consumable packaging • Within instruction manuals
Material Safety Data Sheets • 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 Lincoln Electric consumable product • Available free online at: www.lincolnelectric.com/products/msds/ front
MSDS - Continued • MSDS outlines a product’s: • Identity and composition • Potential hazards • Safe use • Handling information • Manufacturer contact information back
ANSI Z49.1 • ANSI Z49.1: Safety in Welding, Cutting, and Allied Processes • A safety document published by the American Welding Society that covers safe practices in the welding environment • To get your free copy, go to: • www.aws.org/technical/facts/Z49.1-2005-all.pdf • E205: Arc Welding Safety • A safety document summarizing many of the hazards and safe practices for welding • Download and print your own copy at: • http://content.lincolnelectric.com/pdfs/products/literature/e205.pdf • Free copies available from Lincoln Electric at: • www.lincolnelectric.com/products/litrequest • Access the E-learning Site @ www.agedlearning.com
Arc Welding Safety • Protect yourself and others from potential hazards including: • Fumes and Gases • Electric Shock • Arc Rays • Fire and Explosion Hazards • Noise • Hot objects
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 Fumes and Gases
Electric Shock • 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 Do not make repairs yourself, alert your instructor immediately!
Arc rays can injure eyes and burn skin The welding arc is brighter than the sun Precaution must be taken to protect your eyes and skin from UV radiation Wear correct eye and body protection Arc Rays
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 Fire and Explosion Hazards
Noise • Loud noises can damage your hearing • Keep loud noises at a safe level by using proper hearing protection such as: • Ear plugs • Ear muffs
Protective Clothing 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
Application Activity • TIME TO PRACTICE • Go out to the lab • Demonstrate the use of proper safety precautions such as: • Reading warnings • Using proper protective clothing • Equipment inspection • Keeping your head out of the fume • Proper ventilation
The Arc Welding Circuit • 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
Basic Electricity DC - • 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+ AC
Math Terms in Welding • Believe it or not, a lot of math is used in welding
Can All Metals Be Welded? • Most metals can be welded, but not all • The three most common weldable metals include: • Mild Steel - inexpensive and strong • Stainless Steel – does not rust • Aluminum – does not rust and is light weight Aluminum Mild steel Stainless Steel
Gauge • Material thickness is sometimes measured by gauge from 36 (.004 in) to 3 (.2391 in) • For example, steel gauge and measurement in inches: • 16 gauge = .051” 14 gauge = .064” 12 gauge = .081” 10 gauge = .102” PLEASE NOTE: As the gauge number gets smaller … the material thickness gets larger.
Types of Joints • There are 5 types of joints …
Parts of a Weld Heat Affected Zone Joint and Weld
Groove and fillet welds can be made on many types of joints Fillet and Groove Welds
Fillet Weld Inspection • Fillet welds should: • Have a flat to slightly convex face • Be uniform in appearance • Have equal leg size • Have good wash-in into base materials • This is an example of a good fillet weld:
Welding symbols give the welder specific instructions about the weld including: Placement Size Length Process Any other special notes Welding symbols are Universally used Governed by the AWS Found on engineering drawings What are Welding Symbols? “How to Read Shop Drawings” available at www.jflf.org
Welding symbols contain information about the weld to be made S – leg dimension of the weld Triangle – the weld is to be made on the arrow side of this joint Tail – any additional information required (i.e. position the weld is to be made) Arrow - the joint the welding symbol applies to Welding Symbols
What are Welding Positions? • There are various positions that a weld can be made in:
What are the Responsibilities of a Welder? • Welders have many areas of important responsibilities • These relate to: • Arc Welding Safety • Knowledge – Content • Attitude – Reactions • Skills – Performance • Work Habits – Daily Functions Always keep safety in mind when welding