#1 welding tutorial: types of arc welding
TRANSCRIPT
Clandia Sim22/7/2016Heriot-Watt University
Types of Arc Welding
• SMAW – Shielded metal arc welding
• GTAW – Gas tungsten arc welding
• GMAW – Gas metal arc welding
• SAW – Submerged arc welding
Background
• Rod keep melting
• Covered electrode creates shield
• Avoid oxidation which contaminate the weld
• Spray of metal transfer to the joint >> spatter
SMAW – Sheilded / stick
SMAW – Sheilded / stick
• AWS Electrode E6011
• E – electrode
• 60 – 60,000 psi tensile strength of deposited weld metal
• Digit 1 – welding position suitable for use (all position)
• Digit 1 – covering type and current type (greater number, better shielding)
• Other examples: 6010, 6013, 7018, 7024
SMAW – Sheilded / stick
• Tungsten electrode, not consumable
• Argon or helium mixture shielding
• With or without filler metal (similar to base metal) depend on thickness
GTAW – Tungsten / TIG
GTAW - Tungsten
• MIG / MAG welding
• Arc melts continuously as wire fed automatically
• Sheilded gas: argon, helium, CO2 or gas mixtures
GMAW – Gas metal / MIG
• 3 ways of metal transfer:
GMAW – Gas metal / MIG
1. Short-circuit
• Low heat input
2. Globular
• High heat input• Hard to control the droplets
size
3. Axial Spray
• High heat input• Flat horizontal position
• Highly control axial spray is called pulsed spray transfer (GMAW-P)
GMAW – Gas metal / MIG
GMAW – Gas metal / MIG
• Examples on AWS Class and Product Name
SAW - Submerged
• Arc and molten metal are covered by a layer of powder through chute
• Prevent sparks, spatter, intensive UV radiation and fumes
• Flux is part of the powder, thermal insulator
• Allow deep penetration of heat
• Flat, horizontal position due to the powder
• Circular welds on pipe possible if they rotated
SAW - Submerged
• Consumable electrode wire fed automatically
• 1.5 – 10 mm diameter
• Unfused powder can be recovered, treated and refused
• High speed, productivity, high quality welds
• Shipbuilding, pressure vessels
SAW - Submerged
Thank you very muchAny questions? Just comment