Tungsten-Arc Gas Shielded Welding - Low Carbon Steel — SEG Awards Vocationally-Related Qualification Design and Technology Revision

    This topic covers tungsten-arc gas shielded welding (TAGS) on low carbon steel, including safety, equipment setup, and welding techniques. Learners must pr

    Topic Synopsis

    This topic covers tungsten-arc gas shielded welding (TAGS) on low carbon steel, including safety, equipment setup, and welding techniques. Learners must produce sound welds and perform destructive tests.

    Key Concepts & Core Principles

    Exam Tips & Revision Strategies

    Common Misconceptions & Mistakes to Avoid

    Examiner Marking Points

    Tungsten-Arc Gas Shielded Welding - Low Carbon Steel

    SEG AWARDS
    vocational

    This topic covers tungsten-arc gas shielded welding (TAGS) on low carbon steel, including safety, equipment setup, and welding techniques. Learners must produce sound welds and perform destructive tests.

    1
    Learning Outcomes
    3
    Assessment Guidance
    3
    Key Skills
    1
    Key Terms
    4
    Assessment Criteria

    Assessment criteria

    SEG Awards Level 2 Certificate in Welding Techniques and Skills

    Topic Overview

    The SEG Awards Level 2 Certificate in Welding Techniques and Skills provides a comprehensive introduction to the core welding processes used in engineering and manufacturing. This qualification covers manual metal arc (MMA), metal inert gas (MIG), and tungsten inert gas (TIG) welding, along with essential health and safety practices. Students will learn to prepare materials, set up equipment, and produce welded joints to industry standards, making this certificate a vital stepping stone for careers in fabrication, construction, and automotive industries.

    This vocationally-related qualification is designed to blend theoretical knowledge with practical application. You will explore the science behind welding, including heat transfer, metallurgy, and distortion control, while developing hands-on skills in a workshop environment. The course emphasizes quality control and inspection, ensuring you can assess weld integrity and identify common defects. By the end, you will be able to produce butt, fillet, and lap joints in various positions, demonstrating competence that is directly transferable to the workplace.

    Mastering welding techniques is not just about joining metals; it is about understanding how materials behave under extreme conditions and how to create safe, durable structures. This certificate aligns with national occupational standards and prepares you for further study or apprenticeships. Whether you aim to become a coded welder or pursue higher-level engineering qualifications, the skills gained here are fundamental to modern manufacturing and repair industries.

    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 appropriate applications for each.
    • →Joint types and positions: Recognize butt, fillet, lap, and T-joints, and be able to weld in flat, horizontal, vertical, and overhead positions.
    • →Weld defects and inspection: Identify common defects such as porosity, slag inclusion, undercut, and lack of fusion, and know how to prevent them through correct technique.
    • →Health and safety: Follow safe working practices, including use of PPE, fume extraction, fire prevention, and safe handling of gas cylinders.
    • →Metallurgy basics: Understand how heat affects metal properties, including the heat-affected zone (HAZ), and how to control distortion and residual stresses.

    Learning Objectives

    What you need to know and understand

    • 1.1 Identify the need to use appropriate PPE (personal protective equipment) when carrying out TAGS welding activities1.2 Identify the risks associated when welding with TAGS, to include:• arc radiation burns• arc eye• burns from handling hot materials• welding fumes• dangers of using high frequency systems• electric shocks • fire1.3 Identify fire prevention and emergency procedures required in the workplace, to include:• causes of fire• types of fire extinguisher used• evacuation procedures1.4 Identify the main groups of safety signs, to include:• warning• prohibition• mandatory• information signs1.1. Identify the functions of the listed equipment when used with TAGS welding activities, to include:• transformer/generators• transformer/rectifiers• welding inverters• high frequency units• cooling systems• welding lead• welding return lead• welding earth• welding torch• welding shrouds1.2. Identify ancillary equipment used when welding with the TAGS welding process1.3. Identify suitable storage conditions for TAGS filler wires1.4. Identify the filler wires in terms of:• size by diameter• alloying additions1.5. Identify the electrode in terms of:• size by electrode diameter• type of electrodes - alloying additions1.6. Identify appropriate safety checks on TAGS welding equipment prior to use1.7. Prepare to carry out the TAGS welding process to produce welded joints in the PA or PB positions, to include:• production of the correct welding preparation• identify distortion control methods to be used• select the correct electrode type/size• select gas type and flow rate• select filler wire type• set the correct welding current• produce suitable tack welds• weld the joint• post welding cleaning1.8. Identify welding parameters to be used when completing welded joints using TAGS welding, to include:• welding current• electrode slope and tilt angles• filler wire slope and tilt angles• gas flow rates• arc length• electrode polarity1.9. Identify suitable safety checks on welding equipment prior to use1.10. Complete welds on low carbon steel, or stainless steel or aluminium 3 mm or greater in thickness using the TAGS welding process, to include as a minimum:• lap joint• open outside corner • single vee butt joint• tee fillet weldWelds to be completed in the PA or PB position1.11. Describe the limitations of visual inspection on completed welded joints when using the TAGS welding process1.12. Identify and describe typical welding defects that may be found in TAGS welded joints, to include:• undercut • cracks• tungsten inclusions• porosity• arc craters• lack of fusion• lack of penetration 1.13. Check completed welds for:• weld size to cover leg length and throat thickness• weld profile• weld appearance and uniformity• absence of surface defects1.14. Complete the requirements for a report document on welds produced1.15. Prepare and carry out a destructive test on a fillet weld in accordance with the supplied drawing of the welded joint, to include:• nick break test1.16. Prepare and carry out destructive tests on a completed single vee butt weld in accordance with the supplied drawing of the welded joint, to include:• face bend test• root bend test• fracture test1.17. Identify appropriate documentation relating to welding activities, to include:• welding procedure specifications (WPS)• weld inspection report

    Assessment Criteria

    Key criteria assessors look for in your portfolio

    • Identifies PPE and risks associated with TAGS welding.
    • Sets up welding equipment correctly.
    • Produces welds in various joint configurations.
    • Performs destructive tests and interprets results.

    Assessment Guidance

    Guidance for achieving higher grades

    • 💡Practise maintaining a consistent arc length.
    • 💡Know the colour codes for tungsten electrodes.
    • 💡Always use a gas lens for better shielding.
    • 💡Always set up your equipment correctly before starting. Examiners look for methodical preparation: check gas flow, wire feed speed, and amperage settings. A well-prepared candidate demonstrates understanding and reduces the risk of defects.
    • 💡Practice maintaining a consistent travel speed and arc length. Many marks are lost due to uneven bead profiles or excessive spatter. Use a steady hand and watch the puddle, not the arc, to control weld quality.
    • 💡In the theory exam, use technical terms accurately (e.g., 'heat-affected zone' instead of 'hot bit around the weld'). Show you understand the 'why' behind procedures, not just the 'how'. This distinguishes higher-scoring answers.

    Common Mistakes

    Common errors to avoid in your coursework

    • Incorrect electrode preparation leading to contamination.
    • Poor gas shielding causing porosity.
    • Not cleaning the weld area before welding.
    • Misconception: MIG welding is always easier than MMA. Correction: While MIG can be more forgiving on thin materials, MMA requires more skill to maintain arc length and travel speed. Each process has its own challenges and learning curve.
    • Misconception: A shiny weld is always a good weld. Correction: Appearance can be misleading; a shiny weld may have internal defects like lack of fusion or porosity. Proper inspection, including destructive testing, is essential to verify weld quality.
    • Misconception: You can weld any metal with the same settings. Correction: Different metals (e.g., mild steel, stainless steel, aluminium) require specific filler materials, shielding gases, and heat inputs. Using incorrect settings can lead to weak or contaminated welds.

    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 like steel and aluminium).
    • •Familiarity with workshop safety practices and use of hand tools.
    • •Elementary mathematics for measuring and calculating weld sizes and angles.

    Key Terminology

    Essential terms to know

    • 1.1 Identify the need to use appropriate PPE (personal protective equipment) when carrying out TAGS welding activities1.2 Identify the risks associated when welding with TAGS, to include:• arc radiation burns• arc eye• burns from handling hot materials• welding fumes• dangers of using high frequency systems• electric shocks • fire1.3 Identify fire prevention and emergency procedures required in the workplace, to include:• causes of fire• types of fire extinguisher used• evacuation procedures1.4 Identify the main groups of safety signs, to include:• warning• prohibition• mandatory• information signs1.1. Identify the functions of the listed equipment when used with TAGS welding activities, to include:• transformer/generators• transformer/rectifiers• welding inverters• high frequency units• cooling systems• welding lead• welding return lead• welding earth• welding torch• welding shrouds1.2. Identify ancillary equipment used when welding with the TAGS welding process1.3. Identify suitable storage conditions for TAGS filler wires1.4. Identify the filler wires in terms of:• size by diameter• alloying additions1.5. Identify the electrode in terms of:• size by electrode diameter• type of electrodes - alloying additions1.6. Identify appropriate safety checks on TAGS welding equipment prior to use1.7. Prepare to carry out the TAGS welding process to produce welded joints in the PA or PB positions, to include:• production of the correct welding preparation• identify distortion control methods to be used• select the correct electrode type/size• select gas type and flow rate• select filler wire type• set the correct welding current• produce suitable tack welds• weld the joint• post welding cleaning1.8. Identify welding parameters to be used when completing welded joints using TAGS welding, to include:• welding current• electrode slope and tilt angles• filler wire slope and tilt angles• gas flow rates• arc length• electrode polarity1.9. Identify suitable safety checks on welding equipment prior to use1.10. Complete welds on low carbon steel, or stainless steel or aluminium 3 mm or greater in thickness using the TAGS welding process, to include as a minimum:• lap joint• open outside corner • single vee butt joint• tee fillet weldWelds to be completed in the PA or PB position1.11. Describe the limitations of visual inspection on completed welded joints when using the TAGS welding process1.12. Identify and describe typical welding defects that may be found in TAGS welded joints, to include:• undercut • cracks• tungsten inclusions• porosity• arc craters• lack of fusion• lack of penetration 1.13. Check completed welds for:• weld size to cover leg length and throat thickness• weld profile• weld appearance and uniformity• absence of surface defects1.14. Complete the requirements for a report document on welds produced1.15. Prepare and carry out a destructive test on a fillet weld in accordance with the supplied drawing of the welded joint, to include:• nick break test1.16. Prepare and carry out destructive tests on a completed single vee butt weld in accordance with the supplied drawing of the welded joint, to include:• face bend test• root bend test• fracture test1.17. Identify appropriate documentation relating to welding activities, to include:• welding procedure specifications (WPS)• weld inspection report

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