Arc Welding Basics Unit Topics Topics included in

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 2

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 3

Introduction

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 Root Pass or “Stringer Bead” Final weld after several beads are made 5

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 6

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 7

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 8

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 9

Careers in Welding 10

Careers in Welding Job opportunities in welding are changing … Welding can be valuable as a job skill or as a full-time job • • 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 For more information on welding careers, please see the elearning introduction 11

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 12

Application Activity 13

Application Activity • 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? • • • America's Job Bank (http: //www. ajb. dni. us) Classifieds Employment (http: //www. classifieds 2000. com) Yahoo! Careers (http: //careers. yahoo. com/) MONSTER. COM (http: //www. monster. com) (http: //nccer. monster. com) Career. Builder (http: //www. careerbuilder. com) – 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? 14

Welding Safety 15

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 Z 49. 1) – Lincoln Electric’s ‘Arc Welding Safety’ (E 205) 16

Warning Labels • Understand follow all warning labels found: – On welding equipment – With all consumable packaging – Within instruction manuals 17

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/product s/msds/ front 18

MSDS - Continued • MSDS outlines a product’s: § Identity and composition § Potential hazards § Safe use § Handling information § Manufacturer contact information back 19

ANSI Z 49. 1 • ANSI Z 49. 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/Z 49. 1 -2005 -all. pdf • E 205: 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/e 205. pdf – Free copies available from Lincoln Electric at: § www. lincolnelectric. com/products/litrequest • Access the E-learning Site @ www. agedlearning. com 20

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 21

Fumes and Gases • 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 22

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! 23

Arc Rays • 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 24

Fire and Explosion Hazards • 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 25

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 26

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 fireproof pants – Welding cap, helmet and safety glasses – Ear protection – ear plugs and muffs 27

Application Activity 28

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 29

Basic Electricity and Welding 30

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 31

Basic Electricity • Voltage – The electrical potential or pressure that causes current to flow DC - – Measured in Volts DC+ • Current – The movement of charged particles in a specific direction – Measured in Amps AC • Polarity – DC- (Direct Current Electrode Negative) – DC+ (Direct Current Electrode Positive) – AC (Alternating Current) 32

Math Terms and Welding 33

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 34

Metals 35

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 Mild steel Stainless Steel Aluminum 36

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. 37

Types of Joints 38

Types of Joints • There are 5 types of joints … 39

Parts of a Weld 40

Parts of a Weld Heat Affected Joint and Zone Weld 41

Fillet and Groove Welds • Groove and fillet welds can be made on many types of joints 42

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: 43

Welding Symbols 44

What are Welding Symbols? • Welding symbols give • Welding symbols are the welder specific – Universally used instructions about the – Governed by the AWS weld including: – Found on engineering – – – Placement Size Length Process Any other special notes drawings “How to Read Shop Drawings” available at www. jflf. org 45

Welding Symbols • 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 46

Welding Positions 47

What are Welding Positions? • There are various positions that a weld can be made in: 48

Welder Responsibilities 49

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 50

Arc Welding Safety • A welder MUST always follow safe work practices: – 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 Z 49. 1) § Lincoln Electric’s ‘Arc Welding Safety’ (E 205) 51

Knowledge - Content • Welding can teach you about…. – Science when applying metallurgy, chemistry, electricity, etc. – Math when calculating angles, joint design, and weld size – English when communicating and interpreting drawings, codes, and procedures – Technical areas when performing the actual welding applications How much science and math went into the development of this bike? 52

Attitude • The best welders demonstrate a can-do attitude when performing welding processes • This means being able to… – – – Work as a team member Communicate ideas to others Listen to opinions of others Promote a positive attitude Provide solutions to problems Take pride in workmanship These welders work together to inspect a weld. 53

Skills/Performance • A welder must demonstrate technical skills when performing welding processes • A welder must know how to: – Use hand tools and materials, to operate equipment in a safe, accurate, and consistent manner – Acquire and evaluate information needed for problem solving – Complete quality work – Maintain equipment There is no room for poor workmanship in NASCAR 54

Work Habits/Daily Functions • A welder must practice good working habits when performing welding processes • This means being able to … – Follow detailed verbal and written instructions – Maintain workspace, equipment, and tool cleanliness – Correctly fill out, maintain and submit time cards, work assignment cards, and other records as required – Follow safe working practices Agriculture teachers brush up on their welding skills at Lincoln Electric’s Welding Educator’s Workshop 55

Welding Certification 56

Welding Certification • What is a welding certification? – Welding certifications are used to test a welder’s knowledge and welding skill – Certifications are available for many different processes, materials, and positions. • Who certifies welders? – Certification programs are offered by many different types of organizations: § § § Companies Skilled Trades Military Ship Builders Pipelines The American Welding Society 57

Welding Certification • How can you become certified? – Certification testing is available at testing facilities all over the United States – The AWS offers many certifications including: welders, welding inspectors, and welding educators • What is the value of a welding certification? – A welding certification proves that you have passed a test and are qualified for the job – As an AWS certified welder your name is kept in a national database which is used to notify you of jobs open in your area – It is a source of accomplishment and pride 58

English, Math, and Science Connection 59

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 60

National Academic Standards Crosswalk • The unit just completed has covered parts of academic content listed in the National Academic Standards as follows: – NM-PROB. CONN. PK-12. 3: Recognizes and applies mathematics in contexts outside of mathematics. – NLA-STANDARD 1: Uses the general skills and strategies of the writing process. – NLA-STANDARD 7: Uses reading skills and strategies to understand interpret a variety of informational texts. – NS-PHYSICAL SCIENCE: (Experiences) interactions of energy and matter. 61