‫احمد السيد مسعود‬
‫خالد محمد عبد الواحد‬
‫ابراهيم مجدي ابراهيم السيد‬
‫‪SEC 1‬‬
‫‪SEC2‬‬
‫‪SEC1‬‬
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Definition:
Welding is a fabrication process whereby two or more parts are
fused together by means of heat, pressure or both forming a join as the
parts cool.
 The parts that are joined are known as a parent material. The material
added to help form the join is called filler or consumable. The form of
these materials may see them referred to as parent plate or pipe, filler
wire, consumable electrode (for arc welding), etc.
 Consumables are usually chosen to be similar in composition to the
parent material, thus forming a homogenous weld, but there are
occasions, such as when welding brittle cast irons, when a filler with a
very different composition and, therefore, properties is used. These
welds are called heterogeneous.
 The completed welded joint may be referred to as a weldment.
Types of Welding Joints
 Welds Based on Configuration
1- Slot weld
Joint between two overlapping components made
by depositing a fillet weld around the periphery of a hole
in one component so as to join it to the surface of the
other component exposed through the hole.
2- Plug weld
Weld made by filling a hole in one component of a
workpiece with filler metal so as to join it to the surface
of an overlapping component exposed through the hole
(the hole can be circular or oval).
 Weld Based on Penetration
1- Full penetration weld
Welded joint where the weld metal fully penetrates
the joint with complete root fusion. In US the preferred
term is complete joint penetration weld.
2- Partial penetration weld
Weld in which the fusion penetration is
intentionally less than full penetration. In the US the
preferred term is partial joint penetration weld (PJP).
Welds Based on Accessibility
Features of Completed Welds
Fillet weld
Parent Metal
Metal to be joined or surfaced by welding, braze welding or brazing.
Filler Metal
Metal added during welding, braze welding, brazing or surfacing.
Weld Metal
All metal melted during the making of a weld and retained in the weld.
Welding technique sand convinent materials use d
Different processes are determined by the energy source used, with a
variety of different techniques available. Until the end of the 19th century,
forge welding was the only method used, but later processes, such as arc
welding,
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Metal table and the other
Will hol dthe electrode,
known as the shielded-metal arc welder, most people prefer it due to how
easy it is to buy and the lack of a special environment needed to use it.
But the electrodes in a stick welder require frequent replacement
compared with other forms of welding. These include the gas tungsten arc
machines, TIG and gas metal arc welder, known as MIG welders. You will
also need some sort of gas feed with this type of welder.
Charged Electrode
An electrode is the tip of the tool that passes the current from the welder
to the material being welded, making it so hot it becomes liquid. In the
cases of the stick and MIG welders, the type of metal and the heat to melt
it drives the type of electrode tip needed. But in a TIG welder, the
electrode tip is made of non-consumable tungsten, and does not require
replacement.
Wire and Electrode Feeds
Some welds require a feed to strengthen the joint due to the geometry or
weakness of the weld. Stick welding uses the electrode to feed; MIG
welding often uses a wire feed. And TIG welding likewise uses a feed due
to its non-consumable nature.
Most suitable welding techniques: SMAW, DC-TIG, MIG, FCAW,
resistance
Iron-based metals such as steel and stainless steel tend to work with the
highest number of techniques compared to others. Low carbon mild steel
acts as one of the most weldable metals available. Its composition includes
low amounts of elements that can decrease the risk of a failed weld.
Stainless steel has a more complex chemical composition, but it can also
work with multiple techniques that account for oxidation.
ALUMINUM
Most suitable welding techniques: SMAW, AC-TIG, MIG
Grades of aluminum that fall in the 1XXX and 6XXX series can undergo
select welding techniques. A 1XXX series aluminum does not require much
extra effort during the welding process, making it simple to handle.
Meanwhile, a welder can work with 6XXX aluminum if they use proper
welding operations and filler material.
TITANIUM
Most suitable welding technique: DC-TIG
When a welder protects titanium from oxidation, they can use it to achieve
sturdy and long-lasting results. Titanium requires full coverage from a
shielding gas to provide a high level of weld integrity.
CAST IRON
Most suitable welding technique: SMAW
Cast iron poses more difficulty during the welding process than metals such
as steel or aluminum. Its high carbon content requires careful preheating
and heating methods that provide gradual temperature changes.
COPPER AND BRASS
Most suitable welding technique: DC-TIG
Copper and brass have high corrosion resistance that makes them useful
for a variety of welding applications. During the welding process, the welder
needs to account for any alloys in the material that cause cracks or
oxidation.
MAGNESIUM ALLOY
Most suitable welding technique: AC-TIG
A magnesium alloy has similar properties to aluminum. The magnesium in
the alloy has a much lower melting point than oxides, making it critical to
remove oxides before welding.
oxy-acetylene
The oxy-acetylene (and other oxy-fuel gas mixtures) welding torch
remains a mainstay heat source for manual brazing and braze welding, as
well as metal forming, preparation, and localized heat treating
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valve ,smixin gchamber ,nozzl.e
An dals ow ecan notic eits power b ythe color o fthe flame depen do n
the temperature.
neutral since in most cases will have no A neutral flame is named
.chemical effect on the metal being welded
A carburizing flame will produce iron carbide, causing a chemical change
in steel and iron. For this reason a
carburizing flame is not used on metals that absorb carbon.
An oxidizing flame is hotter than a neutral flame and is often used on
.copper and zinc
Welding Torch Flame Types. Shown: Carburizing flame (left), Neutral
flame (center), Oxidizing flame (right)
Temperature Gradient of a Neutral Welding Flame
WELDING SERVICES FROM FAIRLAWN TOOL, INC.
The welding process requires professional techniques and knowledge of
weldable metals. Fairlawn Tool, Inc. provides robotic and manual welding
services as part of our single-source metal fabrication solutions.
Casing welding tha tw euse t oprotect oil and gas wells,
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Safety Equipment
Due to the temperature and elements involved, welding is highly
dangerous and can be lethal if handled incorrectly. Before you touch a
welding setup, wear a welding helmet that protects your eyes, ear plugs,
solid boots to protect your feet from sparks or slag, welding gloves to
protect your hands and leathers to cover the rest of your body. Do not
weld without these, as you will likely get hurt.