Welding Flashcards
What is oxy-acetylene welding?
It is a non-pressure welding process that joins materials using heat from the combustion of air and fuel gas, specifically acetylene and oxygen.
What are the three types of flames used in oxy-fuel gas welding?
Neutral flame, oxidizing flame, and carburizing (reducing) flame.
What is the composition and application of a neutral flame in oxy-acetylene welding?
C₂H₂
₂ = 1:1, used for mild steel, cast iron, stainless steel, copper, aluminum, and their alloys.
What are the characteristics of an oxidizing flame?
C₂H₂
₂ = 1:1.5, flame temperature is 3500°C, and it is used for copper and zinc-based metals. Not applicable for steel.
What is the carburizing flame used for?
Suitable for applications requiring low heat, such as brazing, soldering, and flame hardening.
What is the flame temperature of a carburizing flame, and what are its zones?
3150°C, consisting of an outer cone, intermediate zone, and inner cone.
What gases are used in oxy-fuel gas welding other than acetylene?
Methylacetylene propadiene, hydrogen (not visible), and hydrocarbon-based gases.
What are the advantages of oxy-acetylene welding?
It is versatile, portable, and generates a narrow heat-affected zone (HAZ).
What are the disadvantages of oxy-acetylene welding?
It has a low heat generation rate, produces fumes due to flux, and prolonged heating results in a large HAZ.
What energy source is used in arc welding?
Electrical energy.
What is the temperature of an arc during arc welding?
About 30,000°C.
What are the types of arc welding processes?
Consumable electrode processes and non-consumable electrode processes.
Name some consumable electrode welding processes.
Shielded Metal-Arc Welding (SMAW), Submerged Arc Welding (SAW), Gas-Metal Arc Welding (MIG), Electrogas Welding, Electroslag Welding.
What are some non-consumable electrode welding processes?
Gas Tungsten-Arc Welding (TIG), Atomic Hydrogen Welding, Plasma Arc Welding.
What is Shielded Metal Arc Welding (SMAW) used for?
It is used in general construction, shipbuilding, pipelines, and maintenance, particularly in remote areas.
What thickness of materials is SMAW best suited for?
3 mm to 19 mm, with multiple-pass welding.
What types of joints are used in SMAW?
Lap, butt, corner, edge, and T-joints.
Compare AC and DC welding in terms of power consumption.
AC welding consumes less power, while DC welding consumes more power.
What is Submerged Arc Welding (SAW)?
A process in which the weld zone is submerged under a blanket of flux, using a consumable electrode and a high electric current.
What are the advantages of Submerged Arc Welding (SAW)?
High deposition rates, deep weld penetration, minimal welding fume, no spatter, and high-speed welding of thin steels.
What are the disadvantages of Submerged Arc Welding (SAW)?
It can only be performed on flat and horizontal positions, requires flux cleaning, and slag removal after welding.
What are some applications of Submerged Arc Welding (SAW)?
Used for joining pressure vessels (e.g., boilers), earth-moving equipment, pipes, railroad construction, and shipbuilding.
