What type of flame is used for welding?
A Neutral Oxy Acetylene Flame is used for Welding, Brazing and Silver Soldering most metals and is therefore the most common type of flame to use. A Neutral Flame is also used for Oxy Acetylene Cutting.
There are three different types of flames in gas welding, neutral, carburizing, and oxidizing. The welder can adjust the oxyacetylene flame by adding more or less oxygen to the acetylene flame based on the job requirement.
Oxidizing flames also produce a distinct hissing sound as you open the oxygen valve. When adjusted properly, the inner cone can reach 6300 degrees Fahrenheit, making the oxidizing flame the hottest flame for gas welding.
There are three types of flames natural flame, carburizing flame and oxidizing flame. Natural flame has synchronized mixture of fuel and oxygen, carburizing flame has more fuel and oxidizing flame has more oxygen.
Statement (I): In gas welding process, neutral flame is the most common flame used for welding and cutting stainless steel.
A neutral or slightly reducing flame is recommended for welding aluminum.
A carburizing flame is used in hardfacing and similar processes to obtain fusion between base metal and weld metal without deep melting of the base metal. See also Reducing Flame, Oxidizing Flame, Neutral Flame, and Oxyfuel Gas Welding.
The LPG (propane) is a blue flame because complete combustion creates enough energy to excite and ionize the gas molecules in the flame. The exception is a gas fireplace having yellow or red flames, for a more realistic look.
The neutral flame is the flame most generally used when welding or cutting.
Flame in Gas Welding
Oxy-acetylene flame is mostly used for gas welding because of its high flame temperature (3200 °C). Oxygen is generated by liquefaction of air or by electrolysis of water, and acetylene is produced as a result of a chemical reaction of calcium carbide in contact with water.
What is flux in welding?
Flux is a mixture of various minerals, chemicals, and alloying materials that primarily protect the molten weld metal from contamination by the oxygen and nitrogen and other contaminants in the atmosphere. The addition of certain chemicals and alloys also help to control arc stability and mechanical properties.
The four main types of welding are: Gas Metal Arc Welding (GMAW/MIG), Gas Tungsten Arc Welding (GTAW/TIG), Shielded Metal Arc Welding (SMAW), and Flux Cored Arc Welding (FCAW).
Acetylene is the only fuel gas suitable for gas welding because of its favourable flame characteristics of both high temperature and high propagation rates. Other fuel gases, such as propane, propylene or natural gas, produce insufficient heat input for welding but are used for cutting, torch brazing and soldering.
An oxyfuel gas flame that is neither oxidizing nor reducing. It is a quiet and clean flame obtained by burning approximately 50% acetylene and 50% oxygen. See also Carburizing Flame, Oxidizing Flame, Reducing Flame and Oxyfuel Gas Welding.
Common Voltages are 120 (110/115), 208 (200), 230 (220/240), 460 (440/480), 575 (600), VAC (volts of alter- nating current) with a frequency of 50 or 60 Hz. Welding power source transformers are designed to work with these voltages. Most welding power sources are made to operate on more than one primary voltage value.
Generally, the color of a flame may be red, orange, blue, yellow, or white, and is dominated by blackbody radiation from soot and steam.
Flame cutting (also known as oxy fuel cutting), it is to use the heat burned from oxy fuel gas, to cut steel materials or the hard metals to the panels or profiles required. It can cut steel thickness from 1 mm to 1200 mm.
Oxidizing flame is best for welding brass and bronze because both have copper in it and copper is oxygen free and oxidizing flame have excess of oxygen in it. Also, oxidizing flame produces the highest heat which is required in the welding of both brass and bronze.
Although it isn't the most preferred welding method, torch equipment can be used for welding as well. You can attach a welding tip to the torch handle to get the desired effect. A controlled flame is used to generate a very high temperature that melts the base metal to its puddle or fluid state.
There are basically two gases that are suitable for aluminum welding. Pure argon will give excellent results on all aluminum welding wether it be mig or tig. An argon/Helium mix (the most common being 25% helium is ideal for tig or mig welding aluminum over 1/4"- 50% he for over 1/2" and 75% he for over 1 inch.)
What is difference between oxidizing flame and carburizing flame?
Carburizing flame is obtained when less oxygen than that is required for stoichiometrically complete combustion is supplied. Oxidizing flame is obtained when excess oxygen than that is required for stoichiometrically complete combustion is supplied.
Acetylene. Acetylene generates the hottest flame of all flammable gases, reaching around 3,100 °C when combined with oxygen. Acetylene also generates a concentrated heat supply, as the majority of energy occurs in the primary flame.
A flame with a good oxygen-fuel ratio is called a neutral flame. The color of the flame is semi-transparent purple or blue. This flame is optimal for all intentions, because it does not oxidize or get soot onto surfaces.
Blue flames are the hottest, followed by white. After that, yellow, orange and red are the common colours you'll see in most fires. It's interesting to note that, despite the common use of blue as a cold colour, and red as a hot colour – as they are on taps, for instance – it's the opposite for fire.
Red or yellow flames means there could be a problem, such as incomplete combustion. This color is caused by very fine soot particles produced by the flame, which burns at nearly half the temperature it is supposed to.
There are two types of flames: Non-luminous flame and. Luminous flame.
The most common of the reactive gases used in MIG welding is Carbon Dioxide (CO2). It is the only one that can be used in its pure form without the addition of an inert gas.
Currently oxy-hydrogen is still used when a flame devoid of contaminants – such as the carbon emitted from the combustion of ordinary hydrocarbon fuels - is needed. Forming laboratory glass, polishing acrylic glass, and melting precious metals are common uses of oxy-hydrogen flames today.
| Fuel | Flame Temperature |
|---|---|
| cigarette | 400-700 °C (750-1,300 °F, air) |
| ethane | 1,960 °C (air) |
| hydrogen | 2,660 °C (oxygen), 2,045 °C (air) |
| MAPP | 2,980 °C (oxygen) |
Arc welding is welding using the heat of an arc as a heat source. In arc welding, positive voltage is applied to the electrode (welding rod/wire) and negative voltage is applied to the base material. This makes an arc occur from the base material to the electrode.
What is the most common welding process?
Gas Metal Arc Welding (GMAW/MIG)
This method requires a constant voltage and direct-current power source, and is the most common industrial welding process which includes plate and large bore pipe.
MIG uses a solid wire that is machine-fed to the weld area while TIG uses a non-consumable electrode and a hand-held filler rod to form the weld. These differences mean that MIG and TIG welding processes have their own advantages and disadvantages and preferred applications.
In soldering of metals, flux serves a threefold purpose: it removes any oxidized metal from the surfaces to be soldered, seals out air thus preventing further oxidation, and by facilitating amalgamation improves wetting characteristics of the liquid solder.
describes 'arc length' as the "distance from the tip of the welding electrode to the adjacent surface of the weld pool".
Flux cored arc welding (FCAW), also know as dual shield welding, is a semi-automatic arc welding process that is similar to metal active gas (MAG) welding. FCAW uses a continuous wire fed electrode, a constant-voltage welding power supply, and similar equipment to MAG welding.
A carburizing flame is used in hardfacing and similar processes to obtain fusion between base metal and weld metal without deep melting of the base metal. See also Reducing Flame, Oxidizing Flame, Neutral Flame, and Oxyfuel Gas Welding.
Flame Temperature: Propane produces a flame temperature of ~2800 degree Celsius when burned in oxygen. Acetylene produces a flame temperature of ~3100 degree Celsius along with oxygen. This high flame temperature makes acetylene a suitable choice for gas welding steel.
Acetylene is the only fuel gas suitable for gas welding because of its favourable flame characteristics of both high temperature and high propagation rates. Other fuel gases, such as propane, propylene or natural gas, produce insufficient heat input for welding but are used for cutting, torch brazing and soldering.
A neutral flame is used to weld most of the common metals i.e. mild steel, cast iron, stainless steel, copper and aluminium.
The neutral flame is the flame most generally used when welding or cutting.
What is flux in welding?
Flux is a mixture of various minerals, chemicals, and alloying materials that primarily protect the molten weld metal from contamination by the oxygen and nitrogen and other contaminants in the atmosphere. The addition of certain chemicals and alloys also help to control arc stability and mechanical properties.
Neutral flame produces a hissing sound and the flame is used to weld low Carmon steels and aluminium.
Oxyacetylene welding, commonly referred to as gas welding, is a process which relies on combustion of oxygen and acetylene. When mixed together in correct proportions within a hand-held torch or blowpipe, a relatively hot flame is produced with a temperature of about 3,200 deg.
The LPG (propane) is a blue flame because complete combustion creates enough energy to excite and ionize the gas molecules in the flame. The exception is a gas fireplace having yellow or red flames, for a more realistic look.
For maximum flame temperature in oxygen, the ratio volume of oxygen to fuel gas are 1.2 to 1 for acetylene and 4.3 to 1 for propane. So, there is far more oxygen being consumed when using propane than acetylene. Despite propane being less expensive than acetylene, this is counteracted by the higher oxygen consumption.
Carbon Dioxide (CO2)
Pure CO2 provides very deep weld penetration, which is useful for welding thick material. However, it also produces a less stable arc and more spatter than when it is mixed with other gases. It is also limited to only the short circuit process.
∴ g-atoms of C in gas =3.3844=0.077 g-atoms of H in gas =0.690×218=0.077 ∴ Ratio of C and H atoms in gas is 1:1 Thus, empirical formula of welding gas is CH Empirical formula mass of welding gas =13 Molecular mass = (empirical formula mass)×n ∴ n=25.9813≃2 ∴ Molecular formula =2× empirical formula =2×(CH)=C2H2.
...
Acetylene Cylinder.
The neutral flame is the principal setting for welding or brazing steel. A neutral MAPP gas flame has a primary flame cone abut 1-1/2 to 2 times as long as the primary acetylene flame cone.
What Is Welding Polarity? When you turn on a welding machine, an electrical circuit is formed. The circuit has either a positive or negative pole, and this property is referred to as polarity. Polarity is critical for welders to understand because it directly impacts the quality and strength of the weld.
What is natural flame?
There are three types of flames natural flame, carburizing flame, and oxidizing flame. Natural flame has a synchronized mixture of fuel and oxygen, the carburizing flame has more fuel, and oxidizing flame has more oxygen. Different materials used different flames according to weld condition.