Most 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 andgases can result in eye, nose and throat irritation, dizziness and nausea.Workers in the area who experience these symptoms should leave the areaimmediately, seek fresh air and obtain medical attention. Prolonged exposure towelding fume may cause lung damage and various types of cancer, including lung,larynx and urinary tract. Health effects from certain fumes may include metalfume fever, stomach ulcers, kidney damage and nervous system damage.
Prolongedexposure to manganese fume can cause Parkinson’s–like symptoms. Gases such ashelium, argon, and carbon dioxide displace oxygen in the air and can lead tosuffocation, particularly when welding in confined or enclosed spaces. Carbonmonoxide gas can form, posing a serious asphyxiation hazardFactors that affect worker exposure to weldingfume · Type of weldingprocess· Base metal andfiller metals use· Welding rodcomposition· Location(outside, enclosed space)· Welder workpractices· Air movement · Use ofventilation controlsEffectsof welding fumes · Zinc Oxide fumes –Metal fume fever.· Beryllium -Cancer (lung), berylliosis, chemical pneumonia, long-term. Exposure can resultin shortness of breath, chronic cough, and significant weight loss, Accompaniedby fatigue and general weakness.· Copper -Irritation, damage to the gastrointestinal tract, metal fume fever.
· Fluorides -Irritation, bone damage, fluorosis, skin rashes, pulmonary edema.· Lead –Lead poisoning, central nervous system, blood, kidney, reproductive disorders.· Magnesium -Irritation, metal fume fever.· Molybdenum -Irritation, lung damage, central nervous system.
· Silicon -Irritation, fever.· Tin -Stannosis (i.e., benign lung disease), central nervous system, irritation,immunotoxicity.· Titanium -Lung damage.· Vanadium -Irritation, lung damage.
· Mercury -stomach pain, diarrhea, kidney damage, or respiratory failure, tremors,emotional instability, and hearing damage.· Ozone -headache, chest pain, and dryness of the upper respiratory tract.· Manganese -Acute inflammation of the Lungs, Severe disorder of nervous system, reproductoryproblems, 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,Parkinson disease.· Chromium -Acute and chronic intoxication, dermatitis and Asthma, liver, kidney, andrespiratory cancer (hexavalent chromium insoluble compounds).· Nickel -Potentially Carcinogenic and irritating respiratory track, renal dysfunction,dermatitis, pneumoconiosis, central nervous system and lung damage, cancer. FSW is asolid phase welding, invented by W. Thomas and his colleagues at The WeldingInstitute (TWI), UK, in 1991, permits a wide range of parts and geometries tobe welded.
It requires very low energy input and there is no production offumes, gases, etc., making it friendly to the welders and to our environment.There is neither liberation of gases nor using ofgases.Radiations like ultraviolet, infrared and visible light which are mostly producedin arc welding, laser welding, soldering, and torch welding are not produced inFSW. So this can be the best welding out of all other kinds of unconventionalwelding processes. In the FSW process, parameterselection and tool geometry are among the key factors that determine thequality of the fabricated joint. The value of the different parameters such aswelding speed, rotational speed, tilt angle and pin geometry could lower theforce exerted from the TMAZ section to the tool which improves the quality ofthe weld and less thermal energy is needed for the process prompting bothsheets to reach the plastic state. The plastic flow is responsible forobtaining the weld with high tensile strength and fewer defects and thereforethe tool geometry plays a role in achieving a quality weld.
Thuswe are able to distinguish FSW from other welding as clean, ecofriendly.FSW also has advantages that overcomes most of the demerits thatare in the conventional and even is expected to be the best among all otherun-conventional welding techniques.