WELCOME TO
CWI PREPARATORY
TOPICS: WELDING PROCESSES, BRAZING, SOLDERING & CUTTING PROCESSES
Documents Governing Welding Inspection
Discontinuities
Duties & Responsibilities
Welding Terms and Symbols for welding Brazing and NDE
Metallurgy
NDE
WPS/ PQR
Safety
Welding Brazing Cutting & Soldering
Metal Properties and Destructive Testing
METAL JOINING & CUTTING PROCESSES
Knowledege of processes benefits inspectors
• Helps detect & solve problems
• Leads to better inspection • Gains respect of welders • Gains Cooperation
• Advantages • Limitations • Equipment • Techniques • Problems
What’s important about welding processes to know for the CWI exam?
WELDING TERMINOLOGY PERSONNEL
WELDING OPERATOR
WELDER
SEMI AUTOMATIC
MECHANIZED (MACHINE)
MANUAL
AUTOMATIC
3 BASIC PROCESS GROUPS
Welding
Brazing
Brazing
Shielded Metal Arc Gas Metal Arc Flux Cored Arc Gas Tungsten Arc Submerged Arc
Torch Furnace Induction Resistance Dip Infrared
Oxyfuel Air Carbon Arc
Plasma Arc Mechanical
Plasma Arc Electroslag Oxyacetylene Stud Laser Beam Electron Beam Resistance
Add Soldering to our study list too! There are over 100 welding processes!
DEFINITION OF WELDMENT
A localized coalescence of metals or nonmetals produced either by heating the materials to the welding temperature, with or without the application of pressure or by the application of pressure alone and with or without filler metal.
Middle Ages - Blacksmithing was developed Combination of intense heat and hammering
19th Century - Modern welding first developed First arc between two carbon electrodes, Sir Humphrey Davy
1836 - Edmund Davy discovered acetylene gas
1890 - Carbon arc welding (CAW) First U.S. Patent, arc welding process, issued to C.L. Coffin
Late 1800s - Gas welding & cutting using acetylene, Resistance welding used in construction
Common Features of Welding Processes
All must have: • Sources of Energy
• Most of steels oxidize of 1700 def F and melt at 2700 - 2750 def F
• Source of shielding Due to Oxidation formed by iron & Oxygen combination that must be kept out of the weld
• Iron oxide (rust) is a natural combination.
Filler metal | Optional - Welding without filler metal is autogenous GTAW , PAW, OAW, LBW, EBW
Shielded Metal Arc Welding “Stick” welding Manual Process Polarity DCRP = DCEP | For out of position welding (electrode hotter)
Shielded Metal Arc Welding “Stick” welding Manual Process Polarity DCRP = DCEP | To make work piece hotter
What is duty Cycle ? What is duty Cycle ?
It’s how hard the machine will work
60% duty cycle means the machine will work 6 out of every 10 minutes at maximum rated output
What is volts, amps & ohms?
It’s how hard the machine will work Volts = Pressure | Amps = Flow of electrons Ohms = Resistance
SMAW
Oxygen,Hydrogen Nitrogen
Flux for shielding & Alloying in molten metal
Coating Provides: • Shielding from atmosphere • Deoxidation to eliminate oxygen • Alloying to pull out undesirables • Ionizing Stabilize Arc • Insulation (slag) to slow cool & protect
Fusion Depth
Just try welding without it
SMAW Electrode Identification System
Specification
A 5.1
A 5.5
A 5.4
Family (F No.) Classification
A 5.1 E7018
A 5.5 E7018- A1
A 5.4 E308-15
Chemistry (A No.)
E7018
E7018- A1
E308-15
SMAW Electrode Identification System
EXXXX
E6010
E7018
E7018-1
E11018
Electrodes carry welding current
AWS Filler Metal Specifications
“E” refers to electrode
A5.1 - A5.36 (Rods do not)
SMAW Electrode Identification System
STREGTH | EXXXX
E6010
E7018
E7018-1
E11018
Next two Xs prefer to tensile strength in ksi (1000 psi) Can also be three Xs for higher strengths (ie >100 ksi)
What is a “kip”, as in ksi? 1 kip = 1000lbs
SMAW Electrode Identification System
POSITION | EXXXX
E6010
E7018
E7018-1
E11018
Next two X refers to position 1 = All positions 2 = Flat or horizontal fillets 4 = Downhill progression
*Note : No designation for “3” (retired)
SMAW Electrode Identification System COATING/OPERATING CHARACTERISTICS EXXXX
E7015
E7016
E7018
E7024
Coating determines current, arc characteristics and penetration
Note: Iron powder percentage is based on weight of the covering Usually flux but in XX10 & XX20 different flux
Stainless Steel Electrodes
For all Positions
“L” stands for low carbon Used to protect heat affected zone from sensitization
• E316 / E316L - Weld 316 and 316L • E309 - Weld stainless to Carbon • E308 / E308L - Weld 304 and 304L
E308 “308” type of alloy not tensile stregth
-16 easire to weld than -15 (different flux)
E308L - 16 DCEP or AC Potassium / Titania Coating
E308L - 17 DCEP or AC more silica in coating
SUFFIX
Major Alloy Element(s)
A1 B1
.5% Mo .5% Mo, 5% Cr
B2 B3 B4 C1 C2 C3 D1 D2
.5% Mo, 1.25% Cr 1.0% Mo, 2.25% Cr .5% Mo, 2.0% Cr
Need to have minimum content of one element only
2.5% Ni 3.5% Ni 1.0% Ni
.3% Mo, 1.5% Mn .3% Mo, 1.75% Mn .2% Mo, .3% Cr, .5% Ni, 1.0% Mn... Weathering Steel
G* W
Components of typical SMAW unit
Power supply & controls Power source Electrode lead Work piece lead
Work piece clamp Electrode holder Electrode
• As arc voltage, V, drops, arc current, A, rises • Arc V related to distance from electrode to work • Electrode moved closer, Arc V falls, Arc A rises • Electrode moved away, Arc V rises, Arc A falls • Arc current directly related to heat input • Welder controls heat input to work with arc length Constant Current Power Source
Constant Current Power Source Short arc Length
Low voltage High Current High Heat
Long arc length High Voltage Low Current Low Heat
Simple Equipment
Welds most alloys
ADVANTAGES OF SMAW
Very Portable
Inexpensive
Limatations of SMAW
I can burn that out!
Relatively Slow
Slag Removal
Arc blow - deflection caused by magnetic fields
Stub losses?
Electrode storage considerations
Magnetic Aspects of Current Flow
No matter what the conductor, a magnetic field sets up when current flows through it in 1 direction
Magnetic Aspects of Current Flow
• Change from DC to AC • Weld towards tack welds • Use back step technique • Weld toward work piece lead • Wrap work piece lead cable
• Use runoff plates • Use short arc • Reduce current • Angle electrode opposite • Use heavy tack welds
SMAW Discontinuities
Gas Metal Arc Welding (GMAW)
• Semiautomatic • Machine • Automatic • Commonly referred to as “MIG” • Useful for robotic welding Features: Solid wire electrode Supplied on spools Shielding by gases both inert & reactive Gas mixtured use
GMAW Electrode Identification System
Specification Classification Family (F No.) Chemistry (A No.)
A 5.18 ER70S-6 6 1
A 5.28 ER80S-D2 6 11
GMAW ELECTRODE IDENTIFICATION SYSTEM
ELECTRODE
E R X X S - X
STREGTH
“S” for Solid wire
Denotes tensile strength in ksi Can be 2 or 3 numbers
“Rods” used where wire is fed manually & do not carry current
“ELECTRODES” Carry current
GMAW ELECTRODE IDENTIFICATION SYSTEM
ERXXS - X ELECTRODE
CHEMICAL COMPOSITION Dictates operating characteristics as well as properties of deposited weld Deoxidizing characteristics, the higher the number, the more deoxidizing and higher cost
Components of typical GMAW equipment
Power source & controls Power supply Work piece lead
Work piece clamp Electrode feed unit Electrode supply Welding gun Shielding gas regulator Shielding gas supply Cable assembly
GMAW NOMENCLATURE
Directs shielding Gas
Increase extension produces narrow, high crowned weld bead Desirable electrode extension 1/4 - 1/2" for short arc 1/2 - 1" for other types of transfer
Increased setback allows more time for filler metal to preheat = higher deposition rate
CONSTANT POTENTIAL POWER SOURCE GMAW and occasionallly FCAW
'Self- regulating' (maintains constant arc length) Reduces effect of vertical movement of gun Less operator sensitive Somewhat easier to learn For a given voltage setting is a limited range of amps & wire feed to work with.
GMAW Spray Transfer Mode
Droplets much smaller than wire diameter Occurs as a of combination shielding gas transition voltage Can be achieved only with at least 80% Argon in mixed gases
• Higher amps & volts • Deeper Penetration • Greater Deposition • Base metal hotter
GMAW Spray Transfer Mode
Droplets larger than wire diameter
Transition voltage & wire feeds are lower than those for spray transfer.
• Shielding gas CO2 • Increased spatter • Not as high amps & volts
GMAW Pulsed Transfer Mode
• Welding current is variable between high & low current cycles set by the welder • Provides better heat control • Requires special power source capable of producing a DC output. • Allows more metal in backs off to let it cool without breaking the arc • 2 power sources, 1 providing constant level, other used in addition when high current cycle is enabled
GMAW-S | Short Circuiting Transfer Mode
• Lowest voltage & Wire Feed Disadvantage: Prone to incomplete fusion on heavier sections. • Lowest Heat Good for sheet metal & excessive gaps • Electrode actually comes in contact with base metal • Arc intermittently operating & extinguishing 60 - 200 times per second • Can look good but fool you. Shelf Apperance, likely fusion problems. Smooth transtition better weld. Sounds like 2 bumble bees in a jar when set correctly.
What effects Transfer Mode POWER SUPPLY SHIELDING GAS
TRANSFER MODE
CURRENT LEVEL
VOLTAGE LEVEL
Must change more than one to make a good weld
What is Transition Current?
Advantages of GMAW
Semiautomatic or machine process
Continous Filler metal feed
No slag to remove
Welds most alloys
High Productivity
Clean Process
Lowest hydrogen potential of processes used in structural and similar welding since no flux
Unsuitable for windy conditions · lack of shielding leads to porosity • Little tolerance for contamination due to no flux present • Usually limited to shop welding • Equipment is more complex Consumables • liners, contact tips, rollers replaced often Limitations of GMAW
GMAW Discontinuities
FLUX CORED ARC WELDING (FCAW)
• Tubular electrode • Flux process • Shielding gas optional
FCAW Electrode Identification System
Specification
A 5.20 Mild Steel E70T-1
A 5.29 Low Alloy E91T-1-K2
Classification Family (F No.) Chemistry (A No.)
6 6
6 6
E70C-1 Core Weld electrode was first listed in the FCAW electrode specifications but has now been moved to GMAW 5.18 even though it is a metal core electrode
FCAW Electrode Identification System
1 = ALL POSITIONS 0 = Flat Grooves, Fillets & horizontal fillets
CHEMICAL COMPOSITION
“E” for electrode current carrying
STRENGTH Denotes tensile strength in 10s of thousands Can be 2 or 3 numbers “T” for Tubular Wire -flux filled EXXT - X
FCAW Electrode Identification System
Self -shielded 3, 4, 6, 7, 8, 10, 11
Requires gas 1, 2, 5
E X X T - X
G - Multipass
GS - Single pass
M = Mixed gas required | J = better impacts at lower temps | Ex. E71T - 1MJ
Shielding and Polarity Requirements for Mild Steel FCAW Electrodes
STAINLESS STEEL ELECTRODES
E 308T-X - Welding 304 E 308LT-X -Welding 304L E 316T-X-Welding 316 E 316LT-X - Welding 316L E 309T-X- Welding SS to CS
"E" for electrode, "309" for type of alloy, "T" for tubular
FCAW GUNS - Gas & Self-Shielded
GAS - SHIELDED FCAW EQUIPMENT
Two types of wire feed units: Voltage sensing & Constant feed Extra wire on CC machine to sense arc length and adjust wire feed
SELF - SHIELDED FCAW
Worse for hydrogen cracking. Aging helps eliminate hydrogen prior to testing takes longer for hydrogen to escape
ADVANTAGES OF FCAW
High Productivity
Tolerates Contamination
Suitable for Field work
Deep Penetration
LIMITATONS OF FCAW
Smokey Process
Equipment Complexity
Electrode cost
Slag removal
FCAW Discontinuities
Gas Tungsten Arc Welding (GTAW)
Commonly called “TIG” or “Heliarc”
Inert gas Shielding required
Uses tungsten Electrode
GTAW Nomenclature
GTAW Nomenclature
EWP Pure Tungsten
EWLa-1.5 1.5% Lanthanum EWTh-1 1% thorium
EWLa-2 2% Lanthanum EWLa-2 1% Lanthanum
EWCe-2 2% cerium
EWG 1.5% Lanthanum .08% Zirconium, .08% Yttrium EWTh emits alpha radiation
EWLa-2 2% Thorium
EWG General no specific composition
Carbon Steels GTAW FILLER METALS ER 70S-2, ER 70S-3, etc. Stainless Steel ER 308, ER 308L, ER316 etc.
Did you notice these filler metal classifications look just like the GMAW filler metal classifications?
How long are those rods when we receive them?
Effect of current GTAW
Gas Tungsten Arc Welding Equipment High Frequency maintains arc on reverse cycle, Cycle will jump gap and carry arc so scratch start is not required, even at low amps
Advantages of GTAW
Good for thin materials
High quality welds
No slag
Good Apperance
Mechanization Potential
Very Clean
Advantages of GTAW Low tolerance for contamination
Purging gas expensive
Shielding gas expensive
Relatively slow
GTAW Discontinuities
Causes of Tungsten Inclusion
Tip: Sharp for stainless Rounded for aluminum
Contact between: Tungsten & base material Tungsten & filler metal Excess tungsten extension
Improper tungsten tip grinding Excess current
Submerged Arc Welding (SAW)
A flux process Automatic, machine or semi-automatic Shop &
field applications. Flux classified as Neutral or Active
Submerged Arc Welding (SAW)
Submerged Arc Welding (SAW)
Power supply AC or DC or both on the same weld, same time Up to 1000A with DC, has problems with arc blow higher current with AC, minimizes arc blow. Both AC and DC can be CC or CV. CC most common for DC CC for most conventional AC machines but requires voltage sensing, variable wire feed
FCAW Electrode Identification System
Designates condition of heat treatment which tests were conducted “A” for as welded “P” for PWHT
Classification of electrode use in test (nominal carbon conten 8-16) ie 8 = .08% 16 = .16%
“E” for solid electrode “EC” for composite electrode
FLUX
Tensile Strength in multiples of 10,000 PSI Lowest temparature at which impact strength of weld metal meets or exceeds 20ft-lbs ie 6 = -60F L (low) Mn content M (medium) Mn content H (high) Mn content C (composite) F X X X - E X X X
F = Flux 7 = 70,000 psi minimum tensile strength A = As welded 6 = At least 20 ft-lbs at -60 when using EM12K E = Electrode M = Medium Mn content 12 = .12% nominal carbon content K = Optional to denote silicon killed (deoxidized) Saw Filler Metal Example F7A6 - EM12K - “Killed” Rimmed steel - Cheapest, most impurities Semi-killed - Better Killed - Best, cleanes, highest cost
Submerged Arc Welding (SAW) Equipment
SAW ADVANTAGES
• Deep penetration • High Operator appeal • Mechanized process • Good for overlay of large areas • Hand-held process • No need for eye protection • High deposition rate
LIMITATIONS OF SAW
SLAG REMOVAL
Flat or horizontal grooves and fillets
Needs positioning equipment
Arc not visible to operator
Extensive setup time
Most slag can be easily removed due to flat profile of welds Can regrind and recycle slag as low percentage of flux
Width vs Depth Ratio Limit 1 (width) to 1.2 (depth) ratio
Plasma Arc Welding (PAW)
Similar Power Source
Can be Autogenous
Similar to GTAW
Plasma is an ionized gas with high energy
Plasma Arc Welding (PAW)
Plasma Arc Torch
Constricting nozzle is one difference between PAW & GTAW Also recessed tungsten
Advantages of PAW
Intense arc
Deep penetration
Clean Process
Deep penatrating arc permits keyhole wedding
SW Advantages
• Simple • Fast • Repetitive • Automatic stud feeling (option)
Limitations of PAW
Copper inclusions due to overheating torch
Incomplete Fusion
PAW Discontinuities
Incomplete joint penetration
Tungsten Inclusions -rare
Tunneling keyhole welding
Electroslag Welding ESW • Molten metals & H20 do not mix. BE SAFE!
Electroslag Welding ESW • Consumable Guide Automatic Process Flux process - electrical resistance of flux supplies welding heat Not an “ARC” process, even though arc started Heavy weldments Single pass welds (Vertical casting process)
Joins heavy Sections
Single or multiple electordes
Advantages of ESW
High deposition rates
Minimum joint preparation
Single or multiple electrodes
Limitations of ESW Flux storage Uses water cooled shoes Largely confined to vertical orientation and flat position only Difficult to stop & restart Vertical casting process Very extensive setup time
ESW Discontinuities
Gross Porosity
Large Grains
Cracks
Slag Inclusions
Too big for UT
Gross Shrinkage
Oxyacetylene Welding (OAW)
Termed a Chemical process since heat for welding comes from a chemical reaction. Also called a Flame Process
OAW Flame Adjustment
What are the effects of a flame that is
Oxidizing
Neutral
Carburizing
OAW Equipment Different size tips vary the heat on the work Flame temperature is constant 5400°F for acetylene Variation comes from the different BTUs with different tips Requires larger groove angle to prevent melting of sides prior to root
What shade lens is needed for OFW or OFC?
• “R” Refers to rod • R-45 & R-60 • Digits prefer to minimum tensile strength OAW Filler Metals
• Simple equipment • Suitable for thin materials • Very portable • No electricity required • Can use flux too Advantages of OAW How does flux get in OAW?
• Manual only • Less concentrated heat • Flame adjustment senstive • Very expensive due to gas cost relative to other process Limitations of OAW
• Very slow process • Low productivity
OAW Discontinuities
Severe oxidation
Incomplete Fusion
Severe Carburization
Incomplete joint penetration
Stud Welding • Arc process
• Automatic (mechanized) • Studs can be machine fed • 4 cycle operation
Stud Welding Cycle
A - Insert Stud & ferrule B - Place against work
C - Pull trigger
E - Stud mechanically forced to workpiece D - Arc initiated, melting occurs
Flux on tip cleans weld area “Stand off” tips also used A - Weld completed
SW Advantages • Simple • Fast • Repetitive • Automatic stud feeding (option)
Limitations of SW • Needs clean surface • Equipment malfunction
SW Discontinuities Testing : Hammer test used to check equipment prior to operation
Flash is upset, rim around circumference of stud if incomplete, poor weld Thud vs Ping
Laser Beam Welding (LBW)
• Electronic Radiation
• Concentrated Light Beam
• Very narrow beam of energy
Laser Beam Welding (LBW)
A fusion welding process Heat from concentrated light source Keyhole welding Light beam very small x-section Light can be transmitted by fiber optics or mirrors Non-contact process Shielding gas often required
Advantages of Laser Beam Welding
• Low heat input Less grain growth and distortion . High D/W ratios of 10:1 attainable
. Relatively thick single pass welds (up to 1.25") . Welds thin metals or small diameter wires . Closely spaced components, small welds . Welds wide variety of materials . Beams readily focused and aligned . Not influenced by magnetic fields . Welds metals of dissimilar physical properties • No vacuum or X-ray shielding required • Beams can be transmitted to many work stations
LBW Limitations Alloy reflectivity & thermal conductivity
Joints must be accurately positioned
Surfaces must be forced together
Cost
LBW Discontinuities
POROSITY
EMBRITTLEMENT
Electron Beam Welding (EBW)
• Originally required high vacuum • Can now operate in low or no vacuum • A fusion joining process (similar to LBW) • Heat applied from stream of high-energy electrons
EBW ADVANTAGES
EBW LIMITATIONS
• Similar to LBW • Deeper penetration capability
• Similar to LBW • Vacuum chamber may be required • Vacuum chamber size can limit assembly size • X-rays generated cost
• High purity, especially for vacuum environment • High welding speeds • Ability to change weld shape
EBW Discontinuities
Porosity
Cracking
Root Voids
Resistance Welding
Door Panels in Automotive Industry
Resistance Welding
Heat is obtained from resistance of work pieces as current flows thorugh them Electrodes are usually copper 3 TYPES RSW, PW, RSEW
Advantages of RSW
Semiautomatic or Automatic
Good for thin Materials
Very fast welding < 1 sec/spot
No flux required
RSW Limitations
Electrode must be clean
Metal surfaces must be clean
Inspection of welds may be difficult
Primarily a shop process
RSW Discontinuities
Incomplete Fusion
Cracks
Misalignment of RSEW electrodes
BRAZING
• Torch (TB) • Furnace (FB) • Induction • Resistance • Dip Named after heating method:
• Infrared •Vacuum
BRAZING
Which brazing process does not require flux? Furnace (because it is done in either a vacuum or inert gas)
• Soldering filler metals melt below 840 F SOLDERING
BRAZING WELDING • Base metal not melted in brazing or soldering
• Strong joints possible with all processes if designed properly • Brazing filler metals melt above 840 F (450 C)
BRAZING ASPECTS
• Large Surface Area • Very small clearance • Clean Surfaces • Flux oftend used Capillary action
BRAZING JOINT CONFIGURATIONS
How can we test a braze joint? Peel test, Leak test, ET or UT How is flux introduced in the brazing process? On the rod, Painted on, Paste (dip)
BRAZING FILLER METALS
Wire Strip Foil Paste Preforms
BAlSi BCup
Aluminum - Silicon Copper - Phosoporus Silver Gold Copper Copper - Zinc Magnesium Nickel
BAg BAu BCu RBCuZn BMg Bni
BRAZING ADVANTAGES • Strong Joints • Joins dissimilar metals • Joins metals to nonmetals • Joins “unweldable” metals • Less heat, Less Distortion
BRAZING LIMITATIONS
• Cleanliness requirments • Joint design requirments • Difficult to inspect
BRAZING DISCONTINUITIES
• Voids, unbonded areas • Base metal erosion • Corrosion by flux • Trapped flux
SOLDERING Kinds of Soldering Techniques • Dip • Furnace • Induction • Infrared • Iron • Resistance • Torch • Ultrasonic • Wave
SOLDERING
• Typically performed with a soldering iron, soldering gun or a torch, or occasionally a hot-air pencil. • Uses of a lower melting temp (below 840 F) filler metal than brazing
• Base metals not melted during the joining process like welding • Resulting are not as strong as the base metal, but have adequate strength, electrical conductivity, and water tightness.
Cutting Process
• Oxyfuel Cutting
• Air Carbon Arc Cutting
• Plasma Arc Cutting
• Mechanical Cutting
Oxyfuel Cutting (OFC) & Gouging
Metal is heated to “Kindling” temparature. (approximately 1700 F for steel)
Oxidation reaction takes place, atleast 87% oxygen
It is a chemical process
Oxyfuel Cutting (OFC)
Metal Requirements: • Must burn in Oxygen
• Ignition temperature lower than melting temparature • Low heat conductivity • Material oxide melting temperature lower than melting temperature • Slag must be low viscosity
Oxyfuel Cutting Gases Commonly Used
• Acetylene
• Methane
• Propane
• MPS - Methylacetylene Propadiene
OFC ADVANTAGES
• Simple Equipment • Very Portable • Cuts thin or thick materials • Good Accuracy • Manual or mechanized
MACHINE OFC
Near net shapes achieved by machine OFC
“Near net” means close to production dimensions & requires minimal if any, additional preparation
OFC LIMITATIONS • Cut-edge finishing due to heat affect • High heat input • Heat affected zone • High chrome steels difficult • Fire Hazard - Should have fire watch when using OFC in the field (35 feet)
Air Carbon Arc Cutting (CAC-A) and Gaouging
• Uses carbon electrode with thin Cu sheath for strength
• Arc struck, melts base metal, remove puddle with air blast
Advantages of CAC-A
CAC-A Limitations
• Cuts all metals • Good for Q&T Alloys • Fast and efficient
• Noisy and dirty • Carburizes cut surfaces* • Fire Hazard • Cut surfaces may require grinding to remove carburized layer especially on low carbon stainless steels.
Plasma Arc Cutting (PAC) & Gouging Equipment
Better than OFC on thin materials
Plasma Arc Cutting (PAC)
Recommended Eye Protection for Plasma Arc Cutting (Source: ANSI / AWS C5.2-83, Recommended Practices for Plasma Arc Cutting)
Cutting Current Amperes
Lens Shade Number
Up to 300 300 - 400 400- 800
9 12 14
Advantages of PAC
PAC Limitations
• Cuts all metals • Best for high alloys • Very Clean Cut edge • Very Efficient
• Angular Kerf • Noisy • Fire Hazard
Mechanical Cutting • Shearing • Sawing
• Grinding • Drilling & many others
Mechanical Cutting • Shearing • Sawing Mechanical Cutting Advantages • Very Accurate • Specialized • Efficient • Depending on condition of Equipment • Grinding • Drilling & many others
Mechanical Cutting Limitations
• Often uses S containing cutting oils which creates cracking problems but helps machinability can be slower safety (rotating equipments)
STOP WHEN YOU ARE DONE DON’T STOP WHEN YOU ARE TIRED.
HOMEWORK FOR TONIGHT 1) Questions on pages 322-340 2) Definitions on pages 342-345 3) Then in :
• Part C book (API 1104) • Studyguide questions • Sec 6-9 or • Part D book (AWS D1.1) • CE-2
THANK YOU
www. Rigfab.com Visit Our Website
Page 1 Page 2 Page 3 Page 4 Page 5 Page 6 Page 7 Page 8 Page 9 Page 10 Page 11 Page 12 Page 13 Page 14 Page 15 Page 16 Page 17 Page 18 Page 19 Page 20 Page 21 Page 22 Page 23 Page 24 Page 25 Page 26 Page 27 Page 28 Page 29 Page 30 Page 31 Page 32 Page 33 Page 34 Page 35 Page 36 Page 37 Page 38 Page 39 Page 40 Page 41 Page 42 Page 43 Page 44 Page 45 Page 46 Page 47 Page 48 Page 49 Page 50 Page 51 Page 52 Page 53 Page 54 Page 55 Page 56 Page 57 Page 58 Page 59 Page 60 Page 61 Page 62 Page 63 Page 64 Page 65 Page 66 Page 67 Page 68 Page 69 Page 70 Page 71 Page 72 Page 73 Page 74 Page 75 Page 76 Page 77 Page 78 Page 79 Page 80 Page 81 Page 82 Page 83 Page 84 Page 85 Page 86 Page 87 Page 88 Page 89 Page 90 Page 91 Page 92 Page 93 Page 94 Page 95 Page 96 Page 97 Page 98 Page 99 Page 100 Page 101 Page 102 Page 103 Page 104 Page 105 Page 106 Page 107 Page 108 Page 109 Page 110 Page 111 Page 112 Page 113 Page 114 Page 115 Page 116 Page 117 Page 118 Page 119 Page 120 Page 121 Page 122 Page 123 Page 124 Page 125 Page 126 Page 127 Page 128 Page 129 Page 130 Page 131 Page 132 Page 133 Page 134 Page 135 Page 136 Page 137 Page 138 Page 139 Page 140 Page 141 Page 142 Page 143 Page 144Made with FlippingBook - Share PDF online