Welding technology & design
Radhakrishnan, V. M.
Welding technology & design - Rev. Ed. 2 - New Delhi New Age International (P) Ltd. 2010 - xi,543p.
CONTENTS 1. WELDING PROCESES 1 1.1 Introduction to welding processes 1 1.2 Details of welding processes 4 1.2.1 Gas welding 4 1.2.2 Fusion Arc welding 8 1.2.3 Electrical method 23 1.2.4 Energy method 32 1.2.5 Special methods 38 1.2.6 Selection of welding process 46 1.3 Classification of electrodes 48 1.3.1 Electrode coatings. 48 1.3.2 Classification of electrodes 53 1.3.3 Selection of electrodes. 57 1.4 Weld joint considerations 58 1.4.1 General procedure 58 1.4.2 Type of welded joints. 60 1.4.3 Welding symbols 63 2. WELDING OF MATERIALS AND METALLURGICAL ASPECTS 66 2.1Introduction 66 2.2 Ferrous materials 67 2.2.1 C,C-Mn, C-Mo and low alloy steels 67 2.2.2 Welding of maraging steels 76 2.2.3 HSLA steels 77 2.2.4 Welding of stainless steels 85 2.3 Welding of non-ferrous metals and alloys 95 2.3.1 Welding of aluminium and its alloys 95 2.3.2 Welding of copper and its alloys 97 2.3.3 Welding of titanium alloys 98 2.3.4 Welding of super alloys 99 2.4 Special materials 101 2.4.1 Joining of ceramics 101 2.4.2 Welding of dissimilar metals 103 2.4.3 Hard surfacing and cladding 105 2.5 Welding process and weldability of metals 108 3. STRENGTH AND TOUGHNESS OF WELDED JOINTS 112 3.1 Stress - strain relation 112 3.1.1 Introduction 112 3.1.2 Stress concentration factor 114 3.2 Bending and torsion 117 3.3 Bi-axial and tri-axial stresses 121 3.3.1 General treatment 121 3.3.2 Stresses in cylinders and shells 121 3.3.3 Buckling of plates and columns 123 3.4 Failure criteria 125 3 JS Properties of some typical structural steels 126 3.6 Brittle-ductile fracture 127 3.6.1 Introduction 127 3.6.2 Impact properties 128 3.7 Fracture analysis diagram 133 3.8 Fracture mechanism 137 3.9 Linear elastic fracture mechanics 139 3.9.1 Introduction 139 3.9.2 Stress intensity factor 139 3.9.3 Determination of fracture toughness 141 3.9.4 Types of defects 146 3.9.5 Cracks from stress concentration regions 147 3.9.6 Relation between K,c and other parameters. 149 3.10 Elastic-plastic fracture mechanics 152 3.10.1 Introduction 152 3.10.2 Crack opening displacement 153 3.10.3 Assessment of defects by COD 154 3.10.4 Determination critical COD 157 3.10.5 Mntegral 158 3.10.6 Test procedure for JJC determination 160 3.10.7 Correlation with critical CTOD for a typical aluminium alloy weld 162 3.11 Concept of leak before break 166 3.11.1 Through thickness yielding 166 3.11.2 Yielding in pressure vessel 166 3.11.3 Leak-before-break methodology 167 3.12 Dynamic fracture toughness (Instrumented charpy testing) 168 3.13 Ratio analysis diagram 171 4. RESIDUAL STRESSES AND DISTORTION 175 4.1 Development of residual stresses 175 4.1.1 Introduction 175 4.1.2 Nature and magnitude of residual stresses 176 4.1.3 Factors influencing residual stresses 177 4.2 Typical examples of residual stresses 178 4.2.1 Residual stress in typical joints 178 4.2.2 Sources and effects of residual streses 183 4.2.3 Residual stresses and stress corrosion cracking 186 4.2.4 Relief of residual stresses 187 4.3 Measurement of residual stresses 189 4.3.1 Introduction 189 4.3.2 Hole drilling method 190 4.3.3 X-ray method 191 4.4 Weld Distortion: Causes and effects 193 4.4.1 Types of distortion and causes 193 4.4.2 Distortion details 195 4.4.3 Factors influencing distortion 196 4.4.4 Effect of physical properties on shrinkage 198 4.4.5 Distortion expectancy of some typical materials 198 4.5 Calculation and Control of Distortion 199 4.5.1 Transverse shrinkage 199 4.5.2 Longitudinal distortion 199 4.5.3 Angular distortion 202 4.6 Design considerations to minimise distortion 203 5. FATIGUE OF WELDED JOINTS 208 5.1 S-N relation 208 5.2 Joint types and Classifications 210 5.2.1 Joint types 210 5.2.2 Fatigue of typical joints211 5.2.3 Effect of thickness 215 5.2.4 Classification 216 5.2.5 Prohibited welded joints under cyclic loading 224 5.2.6 Spot welded joint 225 5.3 Defects classification 226 5.4 Effect of defects on fatigue strength of welded joints 229 5.4.1 Porosity and slag inclusions 229 5.4.2 Undercut 231 5.4.3 Lack of penetration 232 5.4.4 Weld bead configuration 233 5.4.5 Welding residual stresses 235 5.5 Effect of mean stress am on fatigue life 236 5.6 Cumulative damage 237 5.7 LEFM analysis of fatigue 241 5.7.1 Fatigue crack growth 241 5.7.2 Life estimation 244 5.7.3 Fatigue crack growth in structural steel 245 5.7.4 Crack growth in welded joint 246 5.7.5 S.I.F. and Crack growth analysis from toe regions 254 5.7.6 Comparison of toe and LOP cracks 257 5.8 Effect of R-ratio and Mean stress on AK,h 259 5.9 Cumulative damage based on LEFM 261 5.10 Life assessment procedure based on LEFM 261 5.10.1 Introduction 261 5.10.2 Data required for assessment 262 5.10.3 Initial and critical defect dimensions 262 5.10.4 Stress intensity factor 263 5.10.5 Assessment procedure 265 6. HIGH TEMPERATURE PROPERTIES AND CREEP OF WELDED JOINTS 267 6.1 High temperature welding 267 6.1.1 Introduction 267 6.1.2 Variables governing weldment properties 271 6.1.3 Welding processes and parameters 271 6.2 High temperature materials and their weldments 272 6.2.1 Heat resistant low alloy steels 272 6.2.2 Stainless steels 277 6.2.3 Welding of super alloys 288 6.3 Specific applications 291 6.3.1 Gas turbine parts 291 6.3.2 Petrochemical components 291 6.3.3 Coal conversion equipments 293 6.4 High temperature and creep properties of welds 294 6.4.1 Cr-Mo steels 294 6.4.2 Austenitic stainless steels 300 6.5 Life estimation and life prediction of high temperature welded components 305 6.5.1 Low cycle fatigue 305 6.5.2 Creep life estimation 307 6.5.3 Remaining life estimation of components 308 6.5.4 Creep crack growth in welded joints 310 6.5.5 Weld behaviour in petroleum reactor pressure vessels 313 7. DESIGN OF TUBULAR JOINTS, PIPES AND PRESSURE VESSELS 317 7.1 Basic parameters of tubular joints 317 7.2 Design Approach for tubes 321 7.2.1 State of Stress 321 7.2.2 Hot Spot Stress 321 7.2.3 Strength criteria and stress calculation 324 7.2.4 Design procedure 329 7.3 Fatigue response of tubular joints 330 7.3.1 General design considerations 330 7.3.2 Design based on hot spot stress/strain range 333 7.4 Pipes 333 7.4.1 General 336 7.4.2 Welding of pipes 337 7.4.3 Node joint fabrication in offshore structure 341 7.4.4 Welding processes forpipe joining 343 7.5 Pressure vessels 345 7.5.1 General considerations 345 7.5.2 Pressure vessel classification 345 7.5.3 Materials used for pressure vessels 347 7.5.4 Electrodes for welding 347 7.5.5 Design aspects 348 7.5.6 Pressure vessel cladding 353 7.5.7 Stress relief by heat-treatment 355 7.5.8 Welded joints at elevated temperature 356 7.6 Codes, standards and specifications for tubes and pipes 356 8. WELD DEFECTS, FAILURE AND Wje. DINGCODES 361 8.1 Classification of weld defects 361 8.2 Fusion weld defects: causes and remedy 364 8.2.1 Porosity 364 8.2.2 Inclusions 366 8.2.3 Incomplete fusion 366 8.3 Weld cracking and failure 368 8.3.1 Genaral 368 8.3.2 Weld metal solidification cracking 369 8.3.3 Hot cracking 372 8.3.4 HA2 cracking 375 8.3.5 Base metal defects 384 8.3.6 Problems with some specific processes and materials 387 8.4 Problems in some specific areas 397 8.4.1 Offshore structure 397 8.4.2 Petro-chemical industries 397 8.4.3 High temperature applications 399 8.5 Welding codes 400 8.5.1 General 400 8.5.2 ISO (International) standard on welded joints 400 8.5.3 Indian standards on codes of practice & recommendations 401 9. WELD TESTING AND QUALIFICATION 404 9.1 Introduction 404 9.2 Basic tests 404 9.2.1 Tensile test 404 9.2.2 Bend Tests 405 9.2.3 Charpy V-notch impact test 406 9.3 Wcldability tests 407 9.3.1 Introduction 407 9.3.2 Hot cracking tests 408 9.3.3 Hydrogen-induced Cracking/Cold cracking test 409 9.4 Special tests 415 9.4.1 Fracture toughness test .415 9.4.2 Fatigue test 416 9.4.3 Stress corrosion testing 418 9.4.4 Prooftesting 419 9.5 Non-destructive tests 420 9.5.1 Introduction 420 9.5.2 Dye penetrant method 420 9.5.3 Magnetic particle testing 421 9.5.4 Radiographic testing 422 9.5.5 Ultrasonic testing 423 9.6 Qualification and performance tests 424 9.6.1 General requirements 424 9.6.2 Welding procedure qualification 424 9.6.3 Welder performance qualification test 425 10. ANALYSIS AND DESIGN OF WELDED JOINTS 427 10.1 Basic Considerations 427 10.1.1 Introduction 427 10.1.2 Common notations 428 10.1.3 Critical dimensions of welded connections429 10.2 Stress analysis in static loading 431 10.2.1 Tensile loads in butt welds 431 10.2.2 Bending load in butt welded joint 432 10.2.3 Partial butt welds subjected to bending 435 10.2.4 Butt welds subjected to torsional moment 436 10.2.5 Fillet welds 437 10.2.6 Concentric and eccentric loading of fillet welds444 10.2.7 Some Typical structural connections 446 10.2.8 Static loading of structural parts 449 10.2.9 Design of spot welds and plug welds 452 10.3 Fracture Mechanics approach 453 10.3.1 Introduction 453 10.3.2 Some typical weld assessments based on fracture mechanics 454 10.3.3 Elliptical surface cracks (part through cracks) 457 10.4 Weld design for distortion and residual stress 459 10.4.1 Weld design for minimum distortion 459 10.4.2 Residual stress 463 10.5 Weld design for dynamic loading, rotating elements and impact loading 467 10.5.1 Fatigue loading 467 10.5.2 Design of rotating elements 471 10.5.3 Design for impact load 474 10.6 Weld design for creep and low cycle fatigue 477 10.6.1Introduction to creep design 477 10.6.2 Weld joint life under bi-axia! creep 477 10.6.3 Design based on limiting dimensional changes 478 10.6.4 Weld design for low cycle fatigue 479 10.7 Weld design for pressure vessels and tubular joints 480 10.7.1 Pressure vessels calculations 480 10.7.2 Weld design of tubular joints 480 1O.8 General design approach 483 APPENDIX 485 BIBLIOGRAPHY 539 INDEX 541
8122416721
671.52 / RAD
Welding technology & design - Rev. Ed. 2 - New Delhi New Age International (P) Ltd. 2010 - xi,543p.
CONTENTS 1. WELDING PROCESES 1 1.1 Introduction to welding processes 1 1.2 Details of welding processes 4 1.2.1 Gas welding 4 1.2.2 Fusion Arc welding 8 1.2.3 Electrical method 23 1.2.4 Energy method 32 1.2.5 Special methods 38 1.2.6 Selection of welding process 46 1.3 Classification of electrodes 48 1.3.1 Electrode coatings. 48 1.3.2 Classification of electrodes 53 1.3.3 Selection of electrodes. 57 1.4 Weld joint considerations 58 1.4.1 General procedure 58 1.4.2 Type of welded joints. 60 1.4.3 Welding symbols 63 2. WELDING OF MATERIALS AND METALLURGICAL ASPECTS 66 2.1Introduction 66 2.2 Ferrous materials 67 2.2.1 C,C-Mn, C-Mo and low alloy steels 67 2.2.2 Welding of maraging steels 76 2.2.3 HSLA steels 77 2.2.4 Welding of stainless steels 85 2.3 Welding of non-ferrous metals and alloys 95 2.3.1 Welding of aluminium and its alloys 95 2.3.2 Welding of copper and its alloys 97 2.3.3 Welding of titanium alloys 98 2.3.4 Welding of super alloys 99 2.4 Special materials 101 2.4.1 Joining of ceramics 101 2.4.2 Welding of dissimilar metals 103 2.4.3 Hard surfacing and cladding 105 2.5 Welding process and weldability of metals 108 3. STRENGTH AND TOUGHNESS OF WELDED JOINTS 112 3.1 Stress - strain relation 112 3.1.1 Introduction 112 3.1.2 Stress concentration factor 114 3.2 Bending and torsion 117 3.3 Bi-axial and tri-axial stresses 121 3.3.1 General treatment 121 3.3.2 Stresses in cylinders and shells 121 3.3.3 Buckling of plates and columns 123 3.4 Failure criteria 125 3 JS Properties of some typical structural steels 126 3.6 Brittle-ductile fracture 127 3.6.1 Introduction 127 3.6.2 Impact properties 128 3.7 Fracture analysis diagram 133 3.8 Fracture mechanism 137 3.9 Linear elastic fracture mechanics 139 3.9.1 Introduction 139 3.9.2 Stress intensity factor 139 3.9.3 Determination of fracture toughness 141 3.9.4 Types of defects 146 3.9.5 Cracks from stress concentration regions 147 3.9.6 Relation between K,c and other parameters. 149 3.10 Elastic-plastic fracture mechanics 152 3.10.1 Introduction 152 3.10.2 Crack opening displacement 153 3.10.3 Assessment of defects by COD 154 3.10.4 Determination critical COD 157 3.10.5 Mntegral 158 3.10.6 Test procedure for JJC determination 160 3.10.7 Correlation with critical CTOD for a typical aluminium alloy weld 162 3.11 Concept of leak before break 166 3.11.1 Through thickness yielding 166 3.11.2 Yielding in pressure vessel 166 3.11.3 Leak-before-break methodology 167 3.12 Dynamic fracture toughness (Instrumented charpy testing) 168 3.13 Ratio analysis diagram 171 4. RESIDUAL STRESSES AND DISTORTION 175 4.1 Development of residual stresses 175 4.1.1 Introduction 175 4.1.2 Nature and magnitude of residual stresses 176 4.1.3 Factors influencing residual stresses 177 4.2 Typical examples of residual stresses 178 4.2.1 Residual stress in typical joints 178 4.2.2 Sources and effects of residual streses 183 4.2.3 Residual stresses and stress corrosion cracking 186 4.2.4 Relief of residual stresses 187 4.3 Measurement of residual stresses 189 4.3.1 Introduction 189 4.3.2 Hole drilling method 190 4.3.3 X-ray method 191 4.4 Weld Distortion: Causes and effects 193 4.4.1 Types of distortion and causes 193 4.4.2 Distortion details 195 4.4.3 Factors influencing distortion 196 4.4.4 Effect of physical properties on shrinkage 198 4.4.5 Distortion expectancy of some typical materials 198 4.5 Calculation and Control of Distortion 199 4.5.1 Transverse shrinkage 199 4.5.2 Longitudinal distortion 199 4.5.3 Angular distortion 202 4.6 Design considerations to minimise distortion 203 5. FATIGUE OF WELDED JOINTS 208 5.1 S-N relation 208 5.2 Joint types and Classifications 210 5.2.1 Joint types 210 5.2.2 Fatigue of typical joints211 5.2.3 Effect of thickness 215 5.2.4 Classification 216 5.2.5 Prohibited welded joints under cyclic loading 224 5.2.6 Spot welded joint 225 5.3 Defects classification 226 5.4 Effect of defects on fatigue strength of welded joints 229 5.4.1 Porosity and slag inclusions 229 5.4.2 Undercut 231 5.4.3 Lack of penetration 232 5.4.4 Weld bead configuration 233 5.4.5 Welding residual stresses 235 5.5 Effect of mean stress am on fatigue life 236 5.6 Cumulative damage 237 5.7 LEFM analysis of fatigue 241 5.7.1 Fatigue crack growth 241 5.7.2 Life estimation 244 5.7.3 Fatigue crack growth in structural steel 245 5.7.4 Crack growth in welded joint 246 5.7.5 S.I.F. and Crack growth analysis from toe regions 254 5.7.6 Comparison of toe and LOP cracks 257 5.8 Effect of R-ratio and Mean stress on AK,h 259 5.9 Cumulative damage based on LEFM 261 5.10 Life assessment procedure based on LEFM 261 5.10.1 Introduction 261 5.10.2 Data required for assessment 262 5.10.3 Initial and critical defect dimensions 262 5.10.4 Stress intensity factor 263 5.10.5 Assessment procedure 265 6. HIGH TEMPERATURE PROPERTIES AND CREEP OF WELDED JOINTS 267 6.1 High temperature welding 267 6.1.1 Introduction 267 6.1.2 Variables governing weldment properties 271 6.1.3 Welding processes and parameters 271 6.2 High temperature materials and their weldments 272 6.2.1 Heat resistant low alloy steels 272 6.2.2 Stainless steels 277 6.2.3 Welding of super alloys 288 6.3 Specific applications 291 6.3.1 Gas turbine parts 291 6.3.2 Petrochemical components 291 6.3.3 Coal conversion equipments 293 6.4 High temperature and creep properties of welds 294 6.4.1 Cr-Mo steels 294 6.4.2 Austenitic stainless steels 300 6.5 Life estimation and life prediction of high temperature welded components 305 6.5.1 Low cycle fatigue 305 6.5.2 Creep life estimation 307 6.5.3 Remaining life estimation of components 308 6.5.4 Creep crack growth in welded joints 310 6.5.5 Weld behaviour in petroleum reactor pressure vessels 313 7. DESIGN OF TUBULAR JOINTS, PIPES AND PRESSURE VESSELS 317 7.1 Basic parameters of tubular joints 317 7.2 Design Approach for tubes 321 7.2.1 State of Stress 321 7.2.2 Hot Spot Stress 321 7.2.3 Strength criteria and stress calculation 324 7.2.4 Design procedure 329 7.3 Fatigue response of tubular joints 330 7.3.1 General design considerations 330 7.3.2 Design based on hot spot stress/strain range 333 7.4 Pipes 333 7.4.1 General 336 7.4.2 Welding of pipes 337 7.4.3 Node joint fabrication in offshore structure 341 7.4.4 Welding processes forpipe joining 343 7.5 Pressure vessels 345 7.5.1 General considerations 345 7.5.2 Pressure vessel classification 345 7.5.3 Materials used for pressure vessels 347 7.5.4 Electrodes for welding 347 7.5.5 Design aspects 348 7.5.6 Pressure vessel cladding 353 7.5.7 Stress relief by heat-treatment 355 7.5.8 Welded joints at elevated temperature 356 7.6 Codes, standards and specifications for tubes and pipes 356 8. WELD DEFECTS, FAILURE AND Wje. DINGCODES 361 8.1 Classification of weld defects 361 8.2 Fusion weld defects: causes and remedy 364 8.2.1 Porosity 364 8.2.2 Inclusions 366 8.2.3 Incomplete fusion 366 8.3 Weld cracking and failure 368 8.3.1 Genaral 368 8.3.2 Weld metal solidification cracking 369 8.3.3 Hot cracking 372 8.3.4 HA2 cracking 375 8.3.5 Base metal defects 384 8.3.6 Problems with some specific processes and materials 387 8.4 Problems in some specific areas 397 8.4.1 Offshore structure 397 8.4.2 Petro-chemical industries 397 8.4.3 High temperature applications 399 8.5 Welding codes 400 8.5.1 General 400 8.5.2 ISO (International) standard on welded joints 400 8.5.3 Indian standards on codes of practice & recommendations 401 9. WELD TESTING AND QUALIFICATION 404 9.1 Introduction 404 9.2 Basic tests 404 9.2.1 Tensile test 404 9.2.2 Bend Tests 405 9.2.3 Charpy V-notch impact test 406 9.3 Wcldability tests 407 9.3.1 Introduction 407 9.3.2 Hot cracking tests 408 9.3.3 Hydrogen-induced Cracking/Cold cracking test 409 9.4 Special tests 415 9.4.1 Fracture toughness test .415 9.4.2 Fatigue test 416 9.4.3 Stress corrosion testing 418 9.4.4 Prooftesting 419 9.5 Non-destructive tests 420 9.5.1 Introduction 420 9.5.2 Dye penetrant method 420 9.5.3 Magnetic particle testing 421 9.5.4 Radiographic testing 422 9.5.5 Ultrasonic testing 423 9.6 Qualification and performance tests 424 9.6.1 General requirements 424 9.6.2 Welding procedure qualification 424 9.6.3 Welder performance qualification test 425 10. ANALYSIS AND DESIGN OF WELDED JOINTS 427 10.1 Basic Considerations 427 10.1.1 Introduction 427 10.1.2 Common notations 428 10.1.3 Critical dimensions of welded connections429 10.2 Stress analysis in static loading 431 10.2.1 Tensile loads in butt welds 431 10.2.2 Bending load in butt welded joint 432 10.2.3 Partial butt welds subjected to bending 435 10.2.4 Butt welds subjected to torsional moment 436 10.2.5 Fillet welds 437 10.2.6 Concentric and eccentric loading of fillet welds444 10.2.7 Some Typical structural connections 446 10.2.8 Static loading of structural parts 449 10.2.9 Design of spot welds and plug welds 452 10.3 Fracture Mechanics approach 453 10.3.1 Introduction 453 10.3.2 Some typical weld assessments based on fracture mechanics 454 10.3.3 Elliptical surface cracks (part through cracks) 457 10.4 Weld design for distortion and residual stress 459 10.4.1 Weld design for minimum distortion 459 10.4.2 Residual stress 463 10.5 Weld design for dynamic loading, rotating elements and impact loading 467 10.5.1 Fatigue loading 467 10.5.2 Design of rotating elements 471 10.5.3 Design for impact load 474 10.6 Weld design for creep and low cycle fatigue 477 10.6.1Introduction to creep design 477 10.6.2 Weld joint life under bi-axia! creep 477 10.6.3 Design based on limiting dimensional changes 478 10.6.4 Weld design for low cycle fatigue 479 10.7 Weld design for pressure vessels and tubular joints 480 10.7.1 Pressure vessels calculations 480 10.7.2 Weld design of tubular joints 480 1O.8 General design approach 483 APPENDIX 485 BIBLIOGRAPHY 539 INDEX 541
8122416721
671.52 / RAD