Basic Electricity and Welding SECTION OVERVIEW: The next slides are meant to explain basic electricity and its relationship to arc welding. TEACHER NOTES: Slides 30-32: Bulleted information on topical area is provided to lead class discussion on the importance of electricity in arc welding processes.

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

Arc Welding Basics SECTION OVERVIEW: Section Overviews are provided on the introductory slides at the front of each topical area to explain the intended use for the slides included in the section. Slide numbers are included on the Section Overview slides for easy reference when preparing for delivery of the slide content. TEACHER NOTES: Teacher Notes are included on the Section Overview slides as a reference tool when making class preparations. Suggested Activities are included for teachers to use to help students gain practical experience with the welding content. However, these are designed to be supplemented by each teacher based on local program needs. Slides have been developed to incorporate content information regarding performance standards from the American Welding Society (AWS) and the National Academic Standards for English, Science, and Math. 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 SECTION OVERVIEW: This slide is meant to start generating conversation and thoughts about content to be covered in this lesson. TEACHER NOTES: Bulleted information on topical areas is provided to lead class discussion on areas which are to be covered in the training.

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 SECTION OVERVIEW: This slide is included to explain the objectives of this unit of study. TEACHER NOTES: Teachers could use this opportunity to give a high-level overview of the importance and application of welding in today’s society.

Introduction SECTION OVERVIEW: These slides are to serve as an opener for discussions about the basics of arc welding. TEACHER NOTES: Slides 4-9: Slides are provided for teachers to use to help students learn about the basics of arc welding. Slide content is designed to serve only as a framework for class discussions and should be supplemented with additional materials based on local program needs. The American Welding Society Contact you local chapter Student memberships available You do not need to be a member to attend a chapter meeting. Find out more at www.aws.org Introduction

Arc welding is most commonly used to join two pieces of metal 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 Steel Pipe – Tack Welded Final weld after several beads are made 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

Welding is so HOT …. it’s COOL! 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

English, Math, and Science Connection SECTION OVERVIEW: The next slides discuss how the content covered in the welding unit is applicable to English, Math, and Science classes. TEACHER NOTES: Slides 59-61: These slides contain information regarding how this welding unit of study relates to the National Academic Standards.

English, Math, and Science Connection Many of the same concepts you learn in other classes are practiced in welding. In what other classes might you study the following terms? 75/25 – gas mixture Volts Amps Degree/hr – cooling rate In/min Angles/degrees Metallurgy Fillet size Current Tension Compression Tensile strength Yield Blueprints Depth/width ratio Preheat temperature Cubic feet per hour

Math Terms and Welding SECTION OVERVIEW: The next few slides are intended to help students connect welding with math applications needed in the work world. TEACHER NOTES: Slide 33-34: This slide contains information to help clarify how several math terms apply to welding.

Math Terms in Welding Believe it or not, a lot of math is used in welding IPM Travel Speed = Inches per Minute Travel Speed The speed the electrode moves along the base material IPM Wire Feed Speed= Inches per Minute Wire Feed Speed The speed at which the wire is fed during wire welding Lbs/hr = Pounds per Hour Electrode deposition rate CFH= Cubic Feet per Hour Shielding gas flow rate (wire welding) PSI= Pounds per Square Inch Tensile strength of a material and the pressure in gas cylinders L = Leg Fillet size measurement % = percent Shielding gas mixture composition

Welding Symbols SECTION OVERVIEW: The next slides are intended to help students learn about welding symbols TEACHER NOTES: Slides 44-46: These slides show some examples of actual welding symbols which can help students more easily grasp the concepts discussed. For more information on welding symbols, see “How to Read Shop Drawings” available for purchase from the James F. Lincoln Foundation (www.jflf.org) To order free posters on the parts of a weld, types of joints, positions and welding symbols go to www.lincolnelectric/products/litrequest/ (Winter 2006)

What are Welding Symbols? 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 “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

Parts of a Weld SECTION OVERVIEW: The next slides are intended to help students develop an understanding of the parts of a weld and of fillet weld inspection TEACHER NOTES: Slides 41-43: Examples of various types of welds are provided to help students visualize the concepts discussed. Common terms and definitions applied to fillet and groove welds: Fillet Weld: Triangular cross section joining two surfaces approximately at right angles to each other in a lap joint, T-joint, or corner joint Groove Weld: A weld made in the groove between work pieces. Fillet Weld Leg: Distance from the joint root to toe of fillet weld Weld Toe: Junction of weld face and base metal Weld Face: Exposed surface on side where welding was done Weld Root: Point at which the back of the weld intersects the base metal surface Actual Throat: Shortest distance between weld root and face of fillet weld Notice the term ‘convex’ in Slide 43. Define for the class and give examples. To order free posters on the parts of a weld, types of joints, positions and welding symbols go to www.lincolnelectric/products/litrequest/ (Winter 2006)

Parts of a Weld Heat Affected Zone Joint and Weld

Fillet and Groove Welds Groove and fillet welds can be made on many types of joints

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 Positions SECTION OVERVIEW: This next slide is intended to help students learn about welding positions. TEACHER NOTES: Slides 47-48: Show examples of welding positions to help students more easily grasp the concepts discussed in this section. To order free posters on the parts of a weld, types of joints, positions and welding symbols go to www.lincolnelectric/products/litrequest/(Winter 2006)

What are Welding Positions? There are various positions that a weld can be made in: