(焊接英语课件)ArcWeldingBasics.ppt

1、Arc Welding Basics2Unit 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 Certification3Objectives Upon successful c

2、ompletion 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

3、 welders6Why 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 go7Why Learn to Weld?Welding is so HOT.its COOL!Welding can help build a successful career so you can get the

4、 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-tech8Basic Steps of Arc Welding Prepare the base materials:remove paint and rust Choose the right welding process Choose the right filler material

5、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 weld9The American Welding Society Who is the AWS?American Welding Society It is a non-profit organization whose membership includes:Individuals S

6、tudents 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 we

7、lding certification10Careers in Welding11Careers in Welding 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 BusinessJob opportunities in welding

8、are changing Welding can be valuable as a job skill or as a full-time job For more information on welding careers,please see the e-learning introduction12How 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

9、money would you make?83%of people with welding jobs were offered medical benefits-Higher than any other work sector except governmentFor more information on welding statistics,please log on to www.bls.gov13Application Activity14Application ActivityLets explore some career possibilities in weldingPle

10、ase log on to a computerWorking with a team member,research the websites to the right and explore information about welding careersIn 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 annuall

11、y 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?Americas Job Bank(http:/www.ajb.dni.us)Classifieds Employment(http:/)Yahoo!Careers(http:/ Safety16 Welding can be safe wh

12、en 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

13、 Processes(ANSI Z49.1)Lincoln Electrics Arc Welding Safety(E205)Arc Welding Safety17Warning Labels Understand and follow all warning labels found:On welding equipment With all consumable packaging Within instruction manuals18Material Safety Data Sheets Material Safety Data Sheets(MSDS)are:Required b

14、y 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: MSDS outlines a products:Identity and composition Potential hazards Safe use Handling information Manufacturer

15、contact informationback20ANSI 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

16、Safety A safety document summarizing many of the hazards and safe practices for welding Download and print your own copy at:http:/ Free copies available from Lincoln Electric at: Access the E-learning Site 21Arc Welding Safety Protect yourself and others from potential hazards including:Fumes and Ga

17、ses Electric Shock Arc Rays Fire and Explosion Hazards Noise Hot objects22Fumes 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 produc

18、t labeling and MSDS for ventilation and respirator requirements23Electric 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 equip

19、ment24Arc 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 protection25Fire and Explosion Hazards Welding sparks can cause fires and explosions Sparks and spatter fr

20、om 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 welding26Noise Loud noises can damage your hearing Keep loud noises at a sa

21、fe level by using proper hearing protection such as:Ear plugs Ear muffs 27Protective ClothingWelders 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

22、 Work boots Welding gloves,jackets,bibs,and fire-proof pants Welding cap,helmet and safety glasses Ear protection ear plugs and muffsWho is he?28Hand and Head Shields Brilliant light caused by electric arc contains two kinds of invisible rays which injure eyes and skin Ultraviolet Infrared Rays affe

23、ct eyes within 50 feet;and skin any distance within 20 feetCopyright The McGraw-Hill Companies,Inc.Permission required for reproduction or display.Fibre-Metal Products Co.Hand shield so person may holdshield in front of faceHand and Head Shields Also called hood or helmet Attached to adjustable head

24、band Allows it to be moved up or down as wearer desires Dependable protection Both hands free to grasp electrode holder Partial protection Must also wear leather or nonflammable cap for adequateprotectionCopyright The McGraw-Hill Companies,Inc.Permission required for reproduction or display.Fibre-Me

25、tal Products Co.Fibre-Metal Products Co.Hand and Head Shields Constructed of heat-resisting,pressed-fiber insulating material Shields fully molded at top and bottom to protect head and neck Usually black to reduce reflection with window frame to hole protective lensFibre-Metal Products Co.Wilson Pro

26、ductsFlip-front welding helmet permits welder to inspect and brush weld without lifting the hood.Chrome leather helmets ideal for hard-to-get-into areas.Copyright The McGraw-Hill Companies,Inc.Permission required for reproduction or display.Head Shield Lens Sizes:2 x 4.5 or 4.5 x 5.25 Colored to scr

27、een out ultraviolet,infrared rays,and most of visible rays Variety of shades of color Density depends on brilliance of arc Varies with size of electrode and volume of current Side exposed to weld pool protected by clear polycarbonate plastic cover lens Protect costly filter lens from molten metal sp

28、atter and breakage(replaced when pitted and clouded)Auto-darkening Electronic Filter Helmet Useful when working close quarters,doing high production work,or avoiding inadvertent arc strikes Single shade or variable shades Filter can switch from light to dark in less than 1/10,000 of a second Battery

29、 powered May have solar battery boosterJackson Products Co.Copyright The McGraw-Hill Companies,Inc.Permission required for reproduction or display.Safety Glasses Should be worn Also behind hood to prevent severe arc flash reaching eyes Can Absorb more than 99.9%harmful ultraviolet rays Worn by other

30、s who work with welders Light in weight,well ventilated,and comfortable Lenses have light tint(Not dark!)and tented side shieldsCopyright The McGraw-Hill Companies,Inc.Permission required for reproduction or display.RobCrandall/The Image WorksProtective Clothing Gloves to protect hands Made of leath

31、er or some other type of fire-resistant material Leather capes,sleeves,shoulder garments with detachable bibs,aprons Split-type apron if sitting down No place to collect hot particles High-top shoes Leggings and spatsCopyright The McGraw-Hill Companies,Inc.Permission required for reproduction or dis

32、play.Department of LaborProtective Clothing 100%cotton or wool Thick enough to prevent injurious untraviolet rays from penetrating to skin Long sleeves Shirts buttoned to neck Shirttails tucked Cuffless pants long enough to cover top of leather bootsMiller Electric Mfg.Co.Copyright The McGraw-Hill C

33、ompanies,Inc.Permission required for reproduction or display.Protective ClothingCopyright The McGraw-Hill Companies,Inc.Permission required for reproduction or display.Further Protection Ear Protection Full ear muffs that cover entire ear or ear plugs Dangers Noise Hot weld spatter or slag entering

34、ear canal Flume Protection Always use proper ventilation to keep head out of fume plume39Application Activity40Application 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 Keepi

35、ng your head out of the fume Proper ventilation41Basic Electricity and Welding42The 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 source43Basic Electricity Voltage The electric

36、al 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-AC44Math Terms and Welding 45Mat

37、h Terms in Welding Believe it or not,a lot of math is used in welding IPM Travel Speed=Inches per Minute Travel SpeedThe speed the electrode moves along the base materialIPM Wire Feed Speed=Inches per Minute Wire Feed SpeedThe speed at which the wire is fed during wire weldingLbs/hr=Pounds per HourE

38、lectrode deposition rate CFH=Cubic Feet per HourShielding gas flow rate(wire welding)PSI=Pounds per Square InchTensile strength of a material and the pressure in gas cylindersL=LegFillet size measurement%=percentShielding gas mixture composition46 Metals47Can All Metals Be Welded?Most metals can be

39、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 weightMild steelStainless SteelAluminum48Gauge Material thickness is sometimes measured by gauge from 36(.004 in)to 3(.2391 in)For exam

40、ple,steel gauge and measurement in inches:PLEASE NOTE:As the gauge number gets smaller the material thickness gets larger.16 gauge=.051”14 gauge=.064”12 gauge=.081”10 gauge=.102”49Types of Joints50Types of Joints There are 5 types of joints 51Parts of a Weld52Parts of a Weld53Fillet and Groove Welds

41、 Groove and fillet welds can be made on many types of joints54Fillet 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:55Welding Symbols56What are Welding

42、 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.org57Welding Symbols We

43、lding 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 to58Welding Positions59What

44、are Welding Positions?There are various positions that a weld can be made in:60Welder Responsibilities61What 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 Habi

45、ts Daily Functions Always keep safety in mind when welding62Arc 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 informat

46、ion Safety in Welding,Cutting,and Allied Processes(ANSI Z49.1)Lincoln Electrics Arc Welding Safety(E205)63Knowledge-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 in

47、terpreting drawings,codes,and procedures Technical areas when performing the actual welding applicationsHow much science and math went into the development of this bike?64Attitude The best welders demonstrate a can-do attitude when performing welding processes This means being able to Work as a team

48、 member Communicate ideas to others Listen to opinions of others Promote a positive attitude Provide solutions to problems Take pride in workmanshipThese welders work together to inspect a weld.65Skills/Performance A welder must demonstrate technical skills when performing welding processes A welder

49、 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 equipmentThere is no room for poor workmanship in NASCAR66Work Habits/Daily Functions A welder must

50、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