عنوان

Heat effects of welding :

3642486428

9783642486425

b568964

Heat effects of welding :

[Book]

temperature field, residual stress, distortion

Dieter Radaj.

Berlin ; New York

Springer-Verlag

2014. ©1992

xxii, 348 pages : illustrations ; 24 cm

Softcover reprint of the hardcover 1st edition 1992 -- title page verso.

1 Introduction.- 1.1 Scope and structuring of contents.- 1.2 Weldability analysis.- 1.3 Residual stresses.- 1.4 Welding residual stresses.- 1.5 Welding residual stress fields.- 1.6 Type examples.- 1.7 Welding deformations.- 1.8 References to related books.- 1.9 Presentation aspects.- 2 Welding temperature fields.- 2.1 Fundamentals.- 2.1.1 Welding heat sources.- 2.1.1.1 Significance of welding temperature fields.- 2.1.1.2 Types of welding heat sources.- 2.1.1.3 Output of welding heat sources.- 2.1.2 Heat propagation laws.- 2.1.2.1 Law of heat conduction.- 2.1.2.2 Law of heat transfer by convection.- 2.1.2.3 Law of heat transfer by radiation.- 2.1.2.4 Field equation of heat conduction.- 2.1.2.5 Initial and boundary conditions.- 2.1.2.6 Thermal material characteristic values.- 2.1.3 Model simplifications relating to geometry and heat input.- 2.1.3.1 Necessity for simplifications.- 2.1.3.2 Simplifications of the geometry.- 2.1.3.3 Spatial simplifications of the heat source.- 2.1.3.4 Time simplifications of heat source.- 2.1.3.5 User questions addressing welding temperature fields.- 2.1.3.6 Numerical solution and comparison with experiments.- 2.2 Global temperature fields.- 2.2.1 Momentary stationary sources.- 2.2.1.1 Momentary point source on the semi-infinite solid.- 2.2.1.2 Momentary line source in the infinite plate.- 2.2.1.3 Momentary area source in the infinite rod.- 2.2.2 Continuous stationary and moving sources.- 2.2.2.1 Moving point source on the semi-infinite solid.- 2.2.2.2 Moving line source in the infinite plate.- 2.2.2.3 Moving area source in the infinite rod.- 2.2.3 Gaussian distribution sources.- 2.2.3.1 Stationary and moving circular source on the semi-infinite solid.- 2.2.3.2 Stationary and moving circular source in the infinite plate.- 2.2.3.3 Stationary strip source in the infinite plate.- 2.2.4 Rapidly moving high-power sources.- 2.2.4.1 Rapidly moving high-power source on the semi-infinite solid.- 2.2.4.2 Rapidly moving high-power source in the infinite plate.- 2.2.5 Heat saturation and temperature equalization.- 2.2.6 Effect of finite dimensions.- 2.2.7 Finite element solution.- 2.2.7.1 Fundamentals.- 2.2.7.2 Ring element model.- 2.2.7.3 Plate element models.- 2.3 Local heat effect on the fusion zone.- 2.3.1 Electric arc as a welding heat source.- 2.3.1.1 Physical-technical fundamentals.- 2.3.1.2 Heat balance and heat source density.- 2.3.1.3 Heat conduction modelling of fusion welding.- 2.3.1.3.1 Melting of the electrode.- 2.3.1.3.2 Fusion of the base metal.- 2.3.1.3.3 Interaction of melting-off and fusion.- 2.3.1.4 Weld pool modelling.- 2.3.1.4.1 Weld pool physics.- 2.3.1.4.2 Welding arc modelling.- 2.3.1.4.3 Hydrostatic surface tension modelling.- 2.3.1.4.4 Hydrodynamic weld pool modelling.- 2.3.1.4.5 Hydrostatic weld shape modelling.- 2.3.1.4.6 Keyhole modelling.- 2.3.2 Flame as a welding heat source.- 2.3.2.1 Physical-technical fundamentals.- 2.3.2.2 Heat balance and heat flow density.- 2.3.3 Resistance heating of weld spots.- 2.3.4 Heat generation in friction welding.- 2.4 Local heat effect on the base metal.- 2.4.1 Microstructural transformation in the heat-affected zone.- 2.4.1.1 Thermal cycle and microstructure.- 2.4.1.2 Time-temperature transformation diagrams.- 2.4.1.3 Evaluation of time-temperature transformation diagrams.- 2.4.2 Modelling of microstructural transformation.- 2.4.3 Cooling rate, cooling time and austenitizing time in single-pass welding.- 2.4.3.1 Cooling rate in solids and thin plates.- 2.4.3.2 Cooling rate in thick plates.- 2.4.3.3 Cooling time in solids and plates.- 2.4.3.4 Austenitizing time in solids and plates.- 2.4.4 Temperature cycles in multi-pass welding.- 2.5 Hydrogen diffusion.- 3 Welding residual stress and distortion.- 3.1 Fundamentals.- 3.1.1 Temperature field as the basis.- 3.1.2 Elastic thermal stress field.- 3.1.3 Elastic-plastic thermal stress field.- 3.1.4 Basic equations of thermomechanics.- 3.1.5 Thermomechanical material characteristic values.- 3.2 Finite element models.- 3.2.1 Intelligent solution.- 3.2.2 Rod element model.- 3.2.3 Ring element model.- 3.2.4 Membrane plate element model in the plate plane.- 3.2.5 Membrane plate element model in the cross-section.- 3.2.6 Solid element model.- 3.3 Shrinkage force and stress source models.- 3.3.1 Longitudinal shrinkage force model.- 3.3.2 Transverse shrinkage force model.- 3.3.3 Application to cylindrical and spherical shells.- 3.3.4 Residual stress source model.- 3.4 Overview of welding residual stresses.- 3.4.1 General statements.- 3.4.2 Weld-longitudinal residual stresses.- 3.4.3 Weld-transverse residual stresses.- 3.4.4 Residual stresses after spot-welding, cladding, and flame cutting.- 3.5 Welding distortion.- 3.5.1 Model simplifications.- 3.5.2 Transverse shrinkage and groove transverse off-set.- 3.5.3 Longitudinal and bending shrinkage.- 3.5.4 Angular shrinkage and twisting distortion.- 3.5.5 Warpage of thin-walled welded components.- 3.6 Measuring methods for residual stress and distortion.- 3.6.1 Significance of test and measurement.- 3.6.2 Strain and displacement measurement during welding.- 3.6.3 Destructive residual stress measurement.- 3.6.3.1 Measurement of uniaxial welding residual stresses.- 3.6.3.2 Measurement of biaxial welding residual stresses.- 3.6.3.3 Measurement of triaxial welding residual stresses.- 3.6.4 Non-destructive residual stress measurement.- 3.6.5 Distortion measurement after welding.- 3.6.6 Similarity relations.- 4 Reduction of welding residual stresses and distortion.- 4.1 Necessities and kinds of measures.- 4.2 Design measures.- 4.3 Material measures.- 4.3.1 Starting points.- 4.3.2 Material characteristic values in the field equations.- 4.3.3 Traditional consideration of the influence of the material.- 4.3.4 Derivation of novel welding suitability indices.- 4.4 Manufacturing measures.- 4.4.1 Starting points.- 4.4.2 Measures prior to and during welding.- 4.4.2.1 Overview.- 4.4.2.2 General measures.- 4.4.2.3 Weld-specific measures.- 4.4.2.4 Thermal measures.- 4.4.2.5 Mechanical measures.- 4.4.2.6 Typical applications.- 4.4.3 Post-weld measures.- 4.4.3.1 Overview.- 4.4.3.2 Hot stress relieving (annealing for stress relief).- 4.4.3.2.1 Hot stress relieving in practice and relevant codes.- 4.4.3.2.2 Stress relaxation tests.- 4.4.3.2.3 Microstructural change during hot stress relieving.- 4.4.3.2.4 Equivalence of annealing temperature and annealing time.- 4.4.3.2.5 Creep laws and creep theories relating to hot stress relieving.- 4.4.3.2.6 Analysis examples and experimental results relating to hot stress relieving.- 4.4.3.3 Cold stress relieving (cold stretching, flame and vibration stress relieving).- 4.4.3.3.1 Rod element model for cold stretching.- 4.4.3.3.2 Notch and crack mechanics of cold stretching.- 4.4.3.3.3 Cold stretching in practice.- 4.4.3.3.4 Flame and induction stress relieving.- 4.4.3.3.5 Vibration stress relieving.- 4.4.3.4 Hammering, rolling, spot compression and spot heating.- 4.4.3.5 Hot, cold and flame straightening.- 5 Survey of strength effects of welding.- 5.1 Methodical and systematical points of view.- 5.2 Hot and cold cracks.- 5.3 Ductile fracture.- 5.4 Brittle fracture.- 5.5 Lamellar tearing type fracture.- 5.6 Creep fracture.- 5.7 Fatigue fracture.- 5.8 Geometrical instability.- 5.9 Corrosion and wear.- 5.10 Strength reduction during welding.

Heat -- Transmission.

Residual stresses.

Welded joints.

Dieter Radaj.

Dieter Radaj

[Book]

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