Tungsten-Arc Gas Shielded Welding - (Vertical) - Aluminium — SEG Awards Vocationally-Related Qualification Design and Technology Revision

    This topic covers tungsten-arc gas shielded (TAG) welding of aluminium in the vertical position, including equipment, parameters, and safety. It involves p

    Topic Synopsis

    This topic covers tungsten-arc gas shielded (TAG) welding of aluminium in the vertical position, including equipment, parameters, and safety. It involves preparing joints, welding, and inspecting welds for defects.

    Key Concepts & Core Principles

    Exam Tips & Revision Strategies

    Common Misconceptions & Mistakes to Avoid

    Examiner Marking Points

    Tungsten-Arc Gas Shielded Welding - (Vertical) - Aluminium

    SEG AWARDS
    vocational

    This topic covers tungsten-arc gas shielded (TAG) welding of aluminium in the vertical position, including equipment, parameters, and safety. It involves preparing joints, welding, and inspecting welds for defects.

    1
    Learning Outcomes
    3
    Assessment Guidance
    3
    Key Skills
    1
    Key Terms
    5
    Assessment Criteria

    Assessment criteria

    SEG Awards Level 3 Diploma in Welding Techniques and Skills

    Topic Overview

    The SEG Awards Level 3 Diploma in Welding Techniques and Skills is a vocationally-related qualification designed for students aiming to become proficient welders in industries such as construction, manufacturing, and engineering. This diploma covers advanced welding processes including Manual Metal Arc (MMA), Metal Inert Gas (MIG), and Tungsten Inert Gas (TIG) welding, along with health and safety regulations, material science, and quality control. Students develop practical skills in preparing joints, selecting appropriate welding parameters, and inspecting welds to industry standards like BS EN ISO 9606-1.

    This qualification is crucial because welding is a core skill in the UK's engineering and manufacturing sectors, with high demand for certified welders. The diploma not only teaches technical competence but also emphasizes problem-solving, precision, and adherence to safety protocols. By mastering these techniques, students can progress to higher-level qualifications or directly into apprenticeships and employment, contributing to the UK's industrial workforce.

    Within the broader Design and Technology curriculum, this diploma bridges theoretical knowledge of materials and processes with hands-on application. It complements subjects like engineering principles and CAD, enabling students to understand how welding integrates into product design and fabrication. The focus on vocational skills prepares learners for real-world challenges, making it a practical choice for those pursuing careers in welding or related fields.

    Key Concepts

    Core ideas you must understand for this topic

    • →Welding Processes: Understand the principles, advantages, and limitations of MMA, MIG, and TIG welding, including equipment setup, electrode selection, and gas shielding.
    • →Material Science: Know how different metals (e.g., carbon steel, stainless steel, aluminium) behave under heat, including thermal expansion, distortion, and metallurgical changes.
    • →Joint Preparation and Geometry: Master the types of welds (butt, fillet, lap) and edge preparations (bevel, J-groove) to ensure penetration and strength.
    • →Health and Safety: Comply with COSHH regulations, use PPE (welding helmet, gloves, fire-resistant clothing), and manage risks like fumes, arc eye, and fire.
    • →Quality Control and Inspection: Perform visual inspection, use gauges for fillet weld size, and understand non-destructive testing (NDT) methods like dye penetrant or ultrasonic testing.

    Learning Objectives

    What you need to know and understand

    • 1.1. Identify the responsibilities of both the employer and the employee when complying with the Health and Safety at Work Act 19741.2. Identify the use of current legislation, to include:• COSHH (Control of Substances Hazardous to Health)• PUWER (Provision and Use of Work Equipment)• RIDDOR (Reporting of Injuries, Diseases, and Dangerous Occurrences Regulations)1.3. Identify the use of a risk assessment procedure1.4. Identify safe working practices when using the TAG welding process, to include working:• in a confined space• at an height above 2 metres • with containers that have held chemicals or flammable liquids • in damp or wet conditions• with hazards from using high frequency units1.5. Describe the function of the equipment used in the TAG welding process, to include:• rectifier• inverter• high frequency units• welding lead cable and clamp• welding return cable and clamp• secondary earth and connector• torch• tungsten• collet• shroud• cooling system• gas supply, regulator and flow meter1.6. Identify suitable maintenance checks that would be required on the items listed in 2.11.7. State the procedures to be followed for the safe storage of welding equipment when the welding activity has been completed1.8. Identify a range of tungsten electrodes that are used for the TAG welding process, to include:• types used• size (diameter)• alloying additions• preparation of electrode tip (shape/dimensions)1.9. Identify a range of filler wires that are used for the TAG welding process, to include:• types used• size (diameter)• alloying additions1.10. Describe the effects of incorrect storage of tungsten electrode and filler wires1.11. State the effect of using damaged tungsten electrode and filler wires when carrying out welding activities1.12. Identify the shielding gas/es used in TAG welding1.13. Identify the function of the shielding gas used in TAG welding1.14. Identify and select the welding parameters to be used when welding in the vertical welding position (PF/PG):• welding current• torch slope and tilt angles• filler wire slope and tilt angles• shielding gas flow rate• arc length• speed of travel1.15. Identify the use of autogenous techniques when using the TAG welding process1.16. Identify suitable welding preparations for the type of joint and material thickness being welded1.17. Identify terms associated with welding preparations, to include:• included angle• angle of bevel• root face dimension• root gap dimension 1.18. Describe the application of distortion control techniques, to include: • pre-setting • restraint• joint geometry • chills• weld sequence1.19. Be able to follow instructions given on a WPS (Welding Procedure Sheet)1.20. Identify appropriate safety checks on the welding equipment prior to use1.21. Select suitable welding parameters to enable the listed joints to be welded by the TAG welding process on low carbon steel or stainless steel or aluminium• tee fillet (PF)• butt (PF)• open outside corner (PF or PG)• lap joint (PF or PG)1.22. Carry out visual inspection of completed welds1.23. Prepare and carry out nick break tests on completed fillet welds1.24. Prepare and carry out destructive tests on completed butt welds, to include:• face bend • root bend• fracture test 1.25. Record the results of the weld examination as detailed in 7.1, 7.2 and 7.31.26. Identify and describe typical defects found in the TAG welding process joints, to include:• cracks• inclusions• undercut• lack of fusion• arc craters• porosity• lack of penetration1.27. Identify possible causes of the defects listed in 8.1

    Assessment Criteria

    Key criteria assessors look for in your portfolio

    • Identify and set up TAG welding equipment correctly.
    • Select appropriate tungsten electrodes, filler wires, and shielding gas.
    • Set welding parameters for vertical welding (PF/PG).
    • Apply distortion control techniques.
    • Perform visual inspection and destructive tests on welds.

    Assessment Guidance

    Guidance for achieving higher grades

    • 💡Memorise typical defects and their causes.
    • 💡Practice setting parameters from a WPS.
    • 💡Understand the importance of cleanliness for aluminium.
    • 💡Tip 1: In practical assessments, always set up your equipment correctly and perform a test run on scrap metal. Examiners look for methodical preparation, including checking gas flow, wire feed speed, and amperage settings.
    • 💡Tip 2: For theory questions, use specific terminology like 'penetration', 'heat-affected zone (HAZ)', and 'dilution'. Refer to British Standards (e.g., BS EN 1011) to show depth of knowledge.
    • 💡Tip 3: When inspecting welds, describe defects using correct terms (e.g., 'undercut', 'slag inclusion', 'lack of fusion') and suggest causes and remedies. This demonstrates understanding beyond just identification.

    Common Mistakes

    Common errors to avoid in your coursework

    • Incorrect electrode preparation or angle.
    • Poor gas flow rate leading to porosity.
    • Inadequate joint preparation causing lack of fusion.
    • Misconception: 'MIG welding is always easier than TIG.' Correction: While MIG is faster, TIG offers greater control for thin materials and aesthetic welds. Each process has its own challenges, and proficiency requires practice in all.
    • Misconception: 'A bigger weld is always stronger.' Correction: Oversized welds can cause distortion and residual stress. The correct weld size is determined by joint design and load requirements, not just adding more filler material.
    • Misconception: 'You don't need to clean the metal if it looks clean.' Correction: Even slight contamination (oil, rust, paint) can cause porosity or lack of fusion. Always clean the joint area with a wire brush or grinder before welding.

    Frequently Asked Questions

    Common questions students ask about this topic

    Before You Start

    Prior knowledge that will help with this topic

    • •Basic understanding of engineering materials (e.g., properties of metals, thermal conductivity).
    • •Familiarity with workshop safety practices and use of hand tools.
    • •Completion of a Level 2 qualification in welding or equivalent experience is recommended but not mandatory.

    Key Terminology

    Essential terms to know

    • 1.1. Identify the responsibilities of both the employer and the employee when complying with the Health and Safety at Work Act 19741.2. Identify the use of current legislation, to include:• COSHH (Control of Substances Hazardous to Health)• PUWER (Provision and Use of Work Equipment)• RIDDOR (Reporting of Injuries, Diseases, and Dangerous Occurrences Regulations)1.3. Identify the use of a risk assessment procedure1.4. Identify safe working practices when using the TAG welding process, to include working:• in a confined space• at an height above 2 metres • with containers that have held chemicals or flammable liquids • in damp or wet conditions• with hazards from using high frequency units1.5. Describe the function of the equipment used in the TAG welding process, to include:• rectifier• inverter• high frequency units• welding lead cable and clamp• welding return cable and clamp• secondary earth and connector• torch• tungsten• collet• shroud• cooling system• gas supply, regulator and flow meter1.6. Identify suitable maintenance checks that would be required on the items listed in 2.11.7. State the procedures to be followed for the safe storage of welding equipment when the welding activity has been completed1.8. Identify a range of tungsten electrodes that are used for the TAG welding process, to include:• types used• size (diameter)• alloying additions• preparation of electrode tip (shape/dimensions)1.9. Identify a range of filler wires that are used for the TAG welding process, to include:• types used• size (diameter)• alloying additions1.10. Describe the effects of incorrect storage of tungsten electrode and filler wires1.11. State the effect of using damaged tungsten electrode and filler wires when carrying out welding activities1.12. Identify the shielding gas/es used in TAG welding1.13. Identify the function of the shielding gas used in TAG welding1.14. Identify and select the welding parameters to be used when welding in the vertical welding position (PF/PG):• welding current• torch slope and tilt angles• filler wire slope and tilt angles• shielding gas flow rate• arc length• speed of travel1.15. Identify the use of autogenous techniques when using the TAG welding process1.16. Identify suitable welding preparations for the type of joint and material thickness being welded1.17. Identify terms associated with welding preparations, to include:• included angle• angle of bevel• root face dimension• root gap dimension 1.18. Describe the application of distortion control techniques, to include: • pre-setting • restraint• joint geometry • chills• weld sequence1.19. Be able to follow instructions given on a WPS (Welding Procedure Sheet)1.20. Identify appropriate safety checks on the welding equipment prior to use1.21. Select suitable welding parameters to enable the listed joints to be welded by the TAG welding process on low carbon steel or stainless steel or aluminium• tee fillet (PF)• butt (PF)• open outside corner (PF or PG)• lap joint (PF or PG)1.22. Carry out visual inspection of completed welds1.23. Prepare and carry out nick break tests on completed fillet welds1.24. Prepare and carry out destructive tests on completed butt welds, to include:• face bend • root bend• fracture test 1.25. Record the results of the weld examination as detailed in 7.1, 7.2 and 7.31.26. Identify and describe typical defects found in the TAG welding process joints, to include:• cracks• inclusions• undercut• lack of fusion• arc craters• porosity• lack of penetration1.27. Identify possible causes of the defects listed in 8.1

    Ready to learn?

    AI-powered learning tailored to this unit

    Related Topics in SEG AWARDS vocational Design and Technology

    12. Advanced Fabrication Processes – Plate (3 mm and Above in Thickness)

    View Topic

    6. Fabrication Processes – Sheet Metal

    View Topic

    Advanced Fabrication Processes – Sheet Metal (below 3 mm in Thickness)

    View Topic

    Engineering Drawing

    View Topic