Welding Engineering Course

Lesson 1 • Heat Transfer and Thermal Cycles

Explains conduction, convection, and radiation in welding and their effect on microstructure. Thermal cycle analysis underpins distortion and residual stress topics in later chapters.

Lesson 2 • Introduction to Welding Processes

Survey major welding categories and their industrial applications. Provides the classification framework referenced throughout the course.

Lesson 3 • Welding Symbols and Drawing Interpretation

Teaches standard welding symbols, joint notation, and weld call-outs on engineering drawings. Symbol literacy is required for procedure and inspection work in subsequent chapters.

Lesson 4 • Metallurgical Principles for Welders

Covers atomic bonding, crystal structures, and phase diagrams relevant to weld metal behaviour. Links material science to practical weld quality outcomes.

Lesson 1 • Flux-Cored and Submerged Arc Welding

Introduces high-deposition processes used in structural and heavy fabrication. Students compare productivity, flux systems, and joint preparation requirements.

Lesson 2 • Gas Tungsten Arc Welding Techniques

Teaches tungsten electrode preparation, filler addition, and torch manipulation for GTAW. Precision skills developed here apply to pipe and aerospace welding in advanced chapters.

Lesson 3 • Shielded Metal Arc Welding Fundamentals

Covers electrode classification, polarity selection, and arc manipulation for SMAW. Establishes manual arc control skills that transfer to other processes.

Lesson 4 • Power Source Technology and Setup

Explains constant-current vs. constant-voltage machines, duty cycle, and output characteristics. Proper machine selection and setup prevent equipment damage and weld defects.

Lesson 1 • Dissimilar Metal Welding Challenges

Examines dilution, intermetallic formation, and coefficient of thermal expansion mismatch. Buttering techniques and filler selection strategies are introduced.

Lesson 2 • Aluminium Alloy Welding Characteristics

Addresses oxide layer removal, porosity from hydrogen, and strength loss in heat-treatable alloys. Proper filler selection and cleaning procedures are emphasised.

Lesson 3 • Carbon and Low-Alloy Steel Weldability

Examines carbon equivalent, hardenability, and hydrogen cracking susceptibility in structural steels. Establishes preheat and interpass temperature requirements used in procedure qualification.

Lesson 4 • Post-Weld Heat Treatment Principles

Covers stress relief, normalising, and solution annealing cycles and their effect on weld properties. PWHT requirements are linked to code compliance and service performance.

Lesson 1 • Welding Procedure Specification Writing

Teaches the essential variables, supplementary variables, and format of a welding procedure specification. A properly written WPS ensures repeatability and regulatory compliance.

Lesson 2 • Weld Joint Geometry and Groove Design

Defines butt, T, corner, lap, and edge joints and their groove configurations. Joint geometry directly affects accessibility, fusion, and residual stress distribution.

Lesson 3 • Heat Input Control and Its Effects

Quantifies heat input from voltage, current, and travel speed and links it to toughness and distortion. Optimising heat input balances productivity with mechanical property requirements.

Lesson 4 • Welder Performance Qualification

Addresses qualification variables, test positions, and range of approval for individual welders. Distinguishes procedure qualification from welder qualification requirements.

Lesson 1 • Residual Stress Origins and Distribution

Covers tensile and compressive residual stress fields, their measurement, and their effect on fatigue and fracture. Residual stress knowledge informs PWHT and peening decisions.

Lesson 2 • Distortion Prevention Strategies

Teaches presetting, back-step sequencing, balanced welding, and restraint fixturing to minimize distortion. Prevention is more cost-effective than post-weld correction.

Lesson 3 • Post-Weld Distortion Correction

Addresses flame straightening, mechanical straightening, and vibratory stress relief for correcting distorted weldments. Correction methods are selected based on material and tolerance requirements.

Lesson 4 • Mechanisms of Welding Distortion

Explains transverse shrinkage, angular distortion, and buckling caused by non-uniform thermal expansion. Understanding distortion types is prerequisite to selecting control methods.

Lesson 1 • Acceptance Criteria and Quality Records

Applies code-based acceptance criteria to NDE results and links findings to disposition decisions. Accurate records support traceability, audits, and continuous improvement.

Lesson 2 • Visual Inspection Techniques and Tools

Covers pre-weld, in-process, and post-weld visual examination using gauges, mirrors, and borescopes. Visual inspection is the first and most cost-effective quality gate.

Lesson 3 • Radiographic Testing of Welds

Addresses film and digital radiography setup, exposure variables, and image interpretation for internal defects. RT provides a permanent record of internal weld quality.

Lesson 4 • Ultrasonic Testing Methods

Covers pulse-echo, angle beam, and phased array UT for volumetric weld examination. UT detects planar defects that radiography may miss and is preferred for thick sections.

Lesson 1 • Weld Discontinuity Types and Origins

Classifies porosity, lack of fusion, undercut, cracks, and inclusions by their formation mechanisms. Linking discontinuity type to process cause enables targeted corrective action.

Lesson 2 • Fracture Mechanics Fundamentals

Introduces stress intensity factor, fracture toughness, and critical crack size concepts. These parameters quantify the tolerance of weld joints to pre-existing flaws.

Lesson 3 • Fatigue Life Improvement Techniques

Covers weld toe grinding, TIG dressing, hammer peening, and high-frequency impact treatment. These methods reduce stress concentration and introduce compressive residual stress.

Lesson 4 • Fitness-for-Service Assessment Methods

Applies fracture mechanics-based assessment levels to evaluate whether detected flaws are acceptable for continued service. FFS analysis avoids unnecessary repair costs.

Lesson 1 • Friction Stir and Solid-State Welding

Explains tool design, rotational speed, and traverse rate for FSW and related solid-state processes. Solid-state joining eliminates fusion defects and is critical for aluminum aerospace structures.

Lesson 2 • Plasma Arc and Plasma Transferred Arc Welding

Addresses plasma gas selection, orifice design, and keyhole plasma welding for full-penetration single-pass joints. Plasma transferred arc is also used for hard-facing applications.

Lesson 3 • Additive Manufacturing via Welding Processes

Introduces wire arc additive manufacturing, directed energy deposition, and layer-by-layer build strategies. WAAM bridges welding and additive manufacturing for large metallic components.

Lesson 4 • Laser Beam and Electron Beam Welding

Covers beam focusing, power density, keyhole formation, and joint fit-up requirements for LBW and EBW. High energy density enables deep penetration with minimal heat input.