commonly used welding
processes emit fumes, gases, electromagnetic radiation,
and noise as byproducts of their
operation. During welding,
workers are potentially
exposed to all of these agents. The fumes
are chemically very complex, arising primarily from
the filler metals and any
electrode coatings or
cores. The potential exposure varies
with the process
and welding conditions employed.
Acute exposure to welding fume and
gases can result in eye, nose and throat irritation, dizziness and nausea.
Workers in the area who experience these symptoms should leave the area
immediately, seek fresh air and obtain medical attention. Prolonged exposure to
welding fume may cause lung damage and various types of cancer, including lung,
larynx and urinary tract. Health effects from certain fumes may include metal
fume fever, stomach ulcers, kidney damage and nervous system damage. Prolonged
exposure to manganese fume can cause Parkinson’s–like symptoms. Gases such as
helium, argon, and carbon dioxide displace oxygen in the air and can lead to
suffocation, particularly when welding in confined or enclosed spaces. Carbon
monoxide gas can form, posing a serious asphyxiation hazard
Factors that affect worker exposure to welding
Type of welding
Base metal and
filler metals use
(outside, enclosed space)
of welding fumes
Zinc Oxide fumes –
Metal fume fever.
Cancer (lung), berylliosis, chemical pneumonia, long-term. Exposure can result
in shortness of breath, chronic cough, and significant weight loss, Accompanied
by fatigue and general weakness.
Irritation, damage to the gastrointestinal tract, metal fume fever.
Irritation, bone damage, fluorosis, skin rashes, pulmonary edema.
Lead poisoning, central nervous system, blood, kidney, reproductive disorders.
Irritation, metal fume fever.
Irritation, lung damage, central nervous system.
Stannosis (i.e., benign lung disease), central nervous system, irritation,
Irritation, lung damage.
stomach pain, diarrhea, kidney damage, or respiratory failure, tremors,
emotional instability, and hearing damage.
headache, chest pain, and dryness of the upper respiratory tract.
Acute inflammation of the Lungs, Severe disorder of nervous system, reproductory
problems, asthenia, dry throat and cough, dyspnoea, encephalopathy; fatigue,
fever, insomnia, lower back pain, malaise, mental confusion, metal fume fever,
paralysis, rales, spastic gait, tightness in the chest, vomiting, weakness,
Acute and chronic intoxication, dermatitis and Asthma, liver, kidney, and
respiratory cancer (hexavalent chromium insoluble compounds).
Potentially Carcinogenic and irritating respiratory track, renal dysfunction,
dermatitis, pneumoconiosis, central nervous system and lung damage, cancer.
FSW is a
solid phase welding, invented by W. Thomas and his colleagues at The Welding
Institute (TWI), UK, in 1991, permits a wide range of parts and geometries to
be welded. It requires very low energy input and there is no production of
fumes, gases, etc., making it friendly to the welders and to our environment.
There is neither liberation of gases nor using of
Radiations like ultraviolet, infrared and visible light which are mostly produced
in arc welding, laser welding, soldering, and torch welding are not produced in
FSW. So this can be the best welding out of all other kinds of unconventional
welding processes. In the FSW process, parameter
selection and tool geometry are among the key factors that determine the
quality of the fabricated joint. The value of the different parameters such as
welding speed, rotational speed, tilt angle and pin geometry could lower the
force exerted from the TMAZ section to the tool which improves the quality of
the weld and less thermal energy is needed for the process prompting both
sheets to reach the plastic state. The plastic flow is responsible for
obtaining the weld with high tensile strength and fewer defects and therefore
the tool geometry plays a role in achieving a quality weld. Thus
we are able to distinguish FSW from other welding as clean, ecofriendly.
FSW also has advantages that overcomes most of the demerits that
are in the conventional and even is expected to be the best among all other
un-conventional welding techniques.