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Day 1 Chapter 1 Introduction
Types of power supplies
Types of electrodes
Process differentiation
Welding Safety
Chapter 2 Terms and Definitions
Welding terminology that is need to discuss the upcoming topics is covered.
Joint types
Weld types
Weld size
Polarity
Metals – ferrous, nonferrous, reactive, and refractory Common abbreviations
Chapter 3 Welding, Brazing and NDT Symbols
About 85% of the fabrication drawings produced by companies contain incorrect welding symbols. Assuming the same percentage of welders interpret the welding symbols correctly, it stands to reason that only about 72% of the welds made are what the engineer expected. Applying the same factor to inspection, it’s possible that the final product will result in 60% of the welds being made the way the engineer expected them to be. This chapter, based on AWS A2.4-98 Standard Symbols for Welding, Brazing, and Nondestructive Examination, reviews how welding, brazing, and NDT symbols should be applied and interpreted.
Elements of a welding symbol
Elements of a joint
Fillet welds
Groove Welds
Multiple reference line to specify order of operations
Contour of completed welds
Specifying NDT
Prequalified and standard joint details (D1.1 and B16.25)
Brazing symbols
Day 2 Chapter 4 Welding Metallurgy
Properties of metals
Steel making processes
Solidification
Allotropic transformation
Alloying – substitutional, interstitial, and intermetallic compounds
Microstructure – ferrite, cementite, pearlite, austenite, and bainite
Controlling microstructure by heat treatments
Weld solidification and resultant microstructure
Weldability
Carbon equivalence
Hydrogen induced cracking/delayed cold cracking
Residual stresses
Low hydrogen welding practices
Base metal specifications
AISI/SAE, ASTM, AMS, UNS
Chapter 4a Practical Welding Problems · Austenitic stainless steel – selecting the proper filler metal and using the WRC 1992 Diagram to predict ferrite number
· Dissimilar welds – austenitic stainless steel to carbon steel – selecting the proper filler metal using the modified WRC 1992 Diagram to predict the ferrite number
· Carbon steel – selecting the proper filler metal, determining proper preheat temperature and designing the weld joint
Chapter 5 Welding Processes
This chapter covers, in detail, four of the most widely used welding processes used by the welding industry. Several other less common welding processes are covered briefly.
Power supplies
Arc voltage and welding amperage
Duty cycle
Electrode types
Shielded metal arc welding
Submerged arc welding
Day 3
Welding Processes continued
Gas tungsten arc welding
Gas metal arc welding
Flux cored arc welding
Welding system requirements Filler metal (electrode) – specifications and classifications
Welding parameters
Plasma arc welding
Electroslag welding
Stud welding
Resistance welding
Brazing / Soldering
Cutting processes
Optional – Time Permitting – depending on class interest
Laser and Electron Beam Welding
Chapter 6 Common Construction Codes
The philosophical differences between ASME and AWS are discussed.
AWS
Prequalification Application specific codes
ASME
No prequalification Application specific code sections
Chapter 7 Procedure and Performance Qualification
The qualification of welding procedures and welders is a complex subject due to the number of codes and standards that have different requirements. This chapter describes the type of welding documentation required and what they are.
Definitions of what is:
a welding procedure specification procedure qualification performance qualification and certification
ASME Section IX
Welding variables
Essential, nonessential, and supplementary essential variables
P, S, F, and A Numbers
Test positions
Testing requirements
Destructive and nondestructive tests
Welding document review – PQR, WPS, and WPTR
Chapter 8 Weld Discontinuities and Defects
This chapter reviews the difference between a discontinuity and a defect. Typical weld discontinuities and defects are discussed and what preventive measure can be taken to minimize the formation of the discontinuities.
Chapter 9 Designing Welds
This chapter addresses some issues the designer should consider when designing a weld.
Fillet welds
Groove welds
Providing proper access for welding
Access holes and clipped corners
Intersecting welds and residual stresses
Aluminum – loss of mechanical properties when welded
Welding dissimilar metals
Chapter 9 Nondestructive Testing
Time permitting, several nondestructive test methods used to examine welds are discussed. The principles of the test method and variations of the test method are discussed
Nondestructive tests vs destructive tests
Typical nondestructive tests
Principles of NDT
Certification of NDT technicians
Written practice
Visual testing
Penetrant testing
Magnetic particle testing
Radiographic testing
Ultrasonic testing
Eddy current testing
Summary of NDT methods and when each is best applied
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