Download Welding for Design Engineers PDF

TitleWelding for Design Engineers
File Size30.4 MB
Total Pages518
Table of Contents
	Historical Background
	Grouping of Welding Processes
	The Welding Arc
		Arc Efficiency
		Voltage Distribution Along the Arc
		Magnetic Field Associated with a Welding Arc
		Effect of Polarity
		Effect of Electrode Extension (Stickout)
		Hydrogen in Weld Metals
	Health and Safety
	Welding Terms and Definitions
Welding Codes and Standards
	Purpose of Standards
	Development of Standards
	Administration of Standards
	CSA Standard W47.1
		Company Certification to CSA Standard W47.1
	CSA Standard W47.2
		Similarity Between W47.1 and W47.2
		Major Differing Provisions Between W47.1 and W47.2
	CSA W48-01
	CSA Standard W59
	CSA Standard W59.2
	CSA Standard S6
	CSA Standard W186-M1990
	CSA Standard W178.1
	CSA W178.2
	National Building Code of Canada (NBC)
		Provincial Building Code
	CSA Standard Z662
	ASME – American Society of Mechanical Engineers
	American Welding Society (AWS)
	AWS Codes of D Series
	AWS A5 Specifications: Filler Metal Specifications
	ISO Standards
Weld Joints and Welding Symbols
	Definition of Joint
		Types of Basic Joints
	Definition of Weld
		Basic Types of Welds
	Groove Weld
		Single Groove Welds
		Double Groove Welds
	Prequalified Joints
	Positions of Welding
		Designation of Welding Positions
		Positions of Groove Welds in Plate
		Positions of Groove Welds in Pipe
	Joint Edge Preparation
	Fundamental Concepts of Welding Symbols
		Weld Symbols, Supplementary Symbols, Welding Symbols
	Basic Weld Symbols
	Supplementary Weld Symbols
		Field Weld Symbol
		Melt-thru Symbol
		Contour Symbol and Finishing of Welds
		All-Around Weld Symbol
	Break in Arrow
	Combined Weld Symbols
	Information in Tail of Welding Symbol
	Extent of Welding Denoted by Symbols
	Multiple Reference Lines
	Complete Penetration
	Groove Welds
		Location of Dimensions for Single-Groove Welds
		Dimensions for Double-Groove Welds
		Depth of Preparation and Groove Weld Size
		Flare-Groove Welds
		Surface Finish and Contour of Groove Welds
		Joints with Backing
	Fillet Welds
		Symbols of Fillet Welds
		Size of Fillet Welds – Equal Leg Fillet Welds
		Minimum and Maximum Fillet Size
		Conventional Fillet Sizes
		Size of Fillet Welds – Unequal Leg Fillet Welds
		Intermittent Fillet Welds
	Plug Welds
		Size of Plug Welds
		Angle of Countersink
		Depth of Filling
		Spacing of Plug Welds
Metal Arc Welding Processes
	Shielded Metal Arc Welding (SMAW)
		Principles of Operation
		Power Sources
		Types of Electrodes
		Classification of Electrodes
		Applications and Limitations of the SMAW Process
		Shielded Metal Arc Welding of Carbon and Low Alloy Steels
	Gas Metal Arc Welding (GMAW)
		Principles of Operation
		Metal Transfer Across the Arc in GMAW
		Shielding Gas
		Advantages and Limitations of the GMAW Process
		Application of Gas Metal Arc Welding Process
		Electrode Wires for Gas Metal Arc Welding
	Flux Cored Arc Welding (FCAW)
		Principles of Operation
		Advantages and Applications of the Cored Wire Processes
		Classification of Cored Wires
		Shielding Gases for Flux Cored Electrodes
	Submerged Arc Welding (SAW)
		Principles of Operation
		Current Type and Equipment
		Advantages and Applications of Submerged Arc Welding
		Multiple Wire Submerged Arc Welding
		Wires and Fluxes for Submerged Arc Welding of Carbonand Low Alloy Steels
		Submerged Arc Welding of Carbon and Low Alloy Steels
Welding Metallurgy
	Basic Concepts of Iron and Steel
	Iron, Cast Iron and Steel
	Phase Transformation During Heating and Cooling
		Phase Diagrams (Iron-Carbon Equilibrium Diagram)
	Effect of Heating and Cooling on Steel
		Slow Cooling of Steel from Above 910°C
		Fast Cooling of Steel from Above 910°C
		How Fast a Cooling Rate is Fast Enough to Form Martensite?
		Heat Treatment of Structural Low Alloy and Quenched and Tempered Steel
	Alloying Elements in Steels
	How Does Hardness Effect Welding?
	Heat Affected Zone (HAZ)
	Weldability of Metals
		Weld Cooling Rate
	Solidification Cracking
	Strength and Toughness in the Weld Zone
	Hydrogen Cracking
		Factors Affecting the Formation of Hydrogen Cracks
		Avoiding Hydrogen Cracking
	Heat Treatment of Steels
		Stress Relief
		Concept of Hardening
		Ways to Harden Steel
		Cold Work (Mechanical Deformation)
		Heat Treatments
	Influence of Welding on Mechanical Properties
	Designation of Steels
		Carbon Steel
		Alloy Steel, Tool Steel and Stainless Steel
	Classification of Steels (Numbering System)
		CSA G40.21 – Canadian Standards Association
Residual Stress and Distortion
	Expansion and Contraction of Metals
	Coefficient of Thermal Expansion and Thermal Stress
	Residual Stresses
		Residual Stresses Induced by Thermal Process
		Residual Stress Induced by Arc Welding
		Residual Stress in Universal Mill Plates with As-Rolled Edges
		Residual Stress Induced by Flame Cutting
		Residual Stress in Welded Wide Flange Shapes
		Residual Stress in Universal Mill Rolled Shapes
		Estimation of Shrinkages
		Distortion Caused by Oxyfuel Gas Cutting
		Distortions Caused by Welding
		Transverse Contraction (Shrinkage) - Angular Distortion
		Longitudinal Expansion and Contraction (Shrinkage)
		Other Causes of Welding Distortion
	Welding Procedure and Distortion
		Welding Procedures
			Weld Pass: SIngle Pass, Multipass or Small Pass
			Travel Speed of Welding Arc
			Uniformity of Heat Input
			Joint Design, Preparation and Fit-Up
			Welding Sequence
			Seam Welding
			Non-Continuous Fillet Welds
			Built-up Structures - Neutral Axis
			Complicated Weldments - Accurate Assembly
	Control and Correction of Distortions
		Control of Distortion
		Correction of Distortion
Fracture and Fatigue of Welded Structures
	Stress-Strain Relationship
	Fracture of Steel Components
	Fracture Surface
	Grain Size Effect
	Transition Temperature and Brittle Fracture
		Design Considerations
		Material Selection
		CSA G40.21 Steels
		Stress Concentration
		Net Section Yielding
		Effect on Brittle Fracture
		Effect of Temperature
		Plain Specimen
		Notched Specimen
		Transition Behaviour
	Effect of Strain Rate
	Fracture Mechanics
	Stress State of Crack Tips
	Stress Intensity Factor
	Fatigue and Fatigue Cracks
		Stress Range Categories and S/N Criteria
		Cumulative Damage Formula
		Fatigue Life Enhancement
		Toe Grinding Method
		Prudent Design Measures
		Prohibited Welds
		Alternate Codes
Welding Design
	Scope and Objectives
		Accessibility for Welding
		Formula for Success
	Design Principles
		Allowable Stress Design (ASD)
		Limit States Design (LSD)
			Load Combinations
	Shear Resistance
	Fillet Weld Strength
	Fillet Weld Groups
	Restrained Members and Moment Connections
		Panel Zone
	Welding of Hollow Structural Section (HSS)
		Typical Joint Configurations
		Possible Failure Modes
		Joint Capacity
		CIDECT Recommendations
	Design Procedures
	Sizing Welds
		PJPG Welds
		CJPG Welds
Weld Faults and Inspection
	Weld Faults Classifications
		Dimensional Faults
		Dimensional Faults Prior to Welding
		Incorrect Joint Preparation and Fit Up
	Distortion or Warpage
	Dimensional Faults
		Incorrect Weld Profiles
		Incorrect Profile and Size of Lap Weld
		Out-of-Line Weld Beads
	Structural Faults in the Weld Zone
		Gas Inclusions
		Causes of Porosity
		Parent Material
		Surface Contaminations
		Insufficient Flux Coverage
		Slag Residue
		Shielding Gas
		Welding Techniques
		Slag Inclusions
		Tungsten Inclusions
		Copper Inclusions
	Fusion Faults
		Incomplete Fusion (Lack of Fusion)
		Incomplete Penetration
		Solidification Cracking
		Hydrogen-Induced Cold Cracking
	Surface Defects (Irregularities)
	Defective Properties (Weld Metal and Joint)
	Summary of Weld Faults
	Welding Inspection
	Methods of Testing
		Visual Welding Inspection
		Liquid Penetrant Inspection
		Magnetic Particle Inspection
		Ultrasonic Testing
Weld Cost Estimating
	Consistent Application of Welding Methods
	Cross-Sectional Area of Weld (At)
	Excess Weld (X)
	Unit Weight of Weld (M)
	Weight of Weld Metal
	Weld Metal Deposition Rate (D)
	Shielding Gas (G)
	Flux for SAW Process (F)
	Process Deposition Factor (Dp)
	Welder/Operator Work Efficiency Factor (Dw)
		Operator Factor
	Weld Cost Estimating Procedure
	Computer Estimating

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