This is when oxygen is rst added to the burning acetylene. The called 'oxidation', but the more speci c and more com- feather is adjusted and made ever smaller by adding in- monly used term in this context is 'combustion'. In the creasing amounts of oxygen to the ame. A welding case of hydrogen, the product of combustion is simply feather is measured as 2X or 3X, with X being the length water. For the other hydrocarbon fuels, water and carbon of the inner ame cone.
The unburned carbon insulates dioxide are produced. The reducing ame is typically used ergy state than the molecules of the fuel and oxygen. In for hard facing operations or backhand pipe welding tech- oxy-fuel cutting, oxidation of the metal being cut typ- niques. The feather is caused by incomplete combustion ically iron produces nearly all of the heat required to of the acetylene to cause an excess of carbon in the ame.
Some of this carbon is dissolved by the molten metal to carbonize it. It is also shipped as a liquid in Dewar type The oxidizing ame is the third possible ame adjust- vessels like a large Thermos jar to places that use large ment.
It occurs when the ratio of oxygen to acetylene re- amounts of oxygen. This ame type is observed when welders It is also possible to separate oxygen from air by passing add more oxygen to the neutral ame. This ame is hot- the air, under pressure, through a zeolite sieve that selec- ter than the other two ames because the combustible tively absorbs the nitrogen and lets the oxygen and argon gases will not have to search so far to nd the necessary pass.
This amount of oxygen, nor heat up as much thermally inert method works well for brazing, but higher-purity oxygen carbon. This ame adjustment is generally not ting. The oxidizing ame creates undesirable ox- ides to the structural and mechanical detriment of most metals. A slightly oxidizing Main article: Oxidizing and reducing ames ame is used in braze-welding and bronze-surfacing while a more strongly oxidizing ame is used in fusion welding certain brasses and bronzes[5] The welder can adjust the oxy-acetylene ame to be car- bonizing aka reducing , neutral, or oxidizing.
Adjust- The size of the ame can be adjusted to a limited extent ment is made by adding more or less oxygen to the acety- by the valves on the torch and by the regulator settings, lene ame.
The neutral ame is the ame most gener- but in the main it depends on the size of the ori ce in the ally used when welding or cutting.
The welder uses the tip. In fact, the tip should be chosen rst according to the neutral ame as the starting point for all other ame ad- job at hand, and then the regulators set accordingly. This ame is attained when welders, as they slowly open the oxygen valve on the torch body, rst see only two ame zones.
The two parts of this ame are the small puddle of molten metal is formed. The puddle is light blue inner cone and the darker blue to colorless outer moved along the path where the weld bead is desired. The inner cone is where the acetylene and the oxy- Usually, more metal is added to the puddle as it is moved gen combine. The tip of this inner cone is the hottest part along by dipping metal from a welding rod or ller rod of the ame.
The metal puddle will and provides enough heat to easily melt steel. This is ac- ner cone the acetylene breaks down and partly burns to complished through torch manipulation by the welder. The ame size is determined by the welding An excess of acetylene creates a carbonizing ame.
This tip size. The workpiece, causing the metal to burn and blowing the re- welder will modify the speed of welding travel to main- sulting molten oxide through to the other side. The ideal tain a uniform bead width. Uniformity is a quality at- kerf is a narrow gap with a sharp edge on either side of tribute indicating good workmanship. Trained welders the workpiece; overheating the workpiece and thus melt- are taught to keep the bead the same size at the beginning ing through it causes a rounded edge.
If the bead gets too wide, the welder increases the speed of welding travel. If the bead gets too narrow or if the weld puddle is lost, the welder slows down the speed of travel. Welding in the vertical or overhead positions is typically slower than welding in the at or horizontal positions. The welder must also keep the ller metal in the hot outer ame zone when not adding it to the puddle to protect ller metal from oxidation.
Do not let the welding ame burn o the ller metal. The metal will not wet into the base metal and will look like a series of cold dots on the base metal. There is very little strength in a cold weld. Fuel Rich Butane Torch Flame When the ller metal is properly added to the molten pud- dle, the resulting weld will be stronger than the original base metal.
Welding lead or 'lead burning' was much more com- mon in the 19th century to make some pipe connec- tions and tanks. Great skill is required but can be quickly learned. In the automotive body collision industry before the s, oxyacetylene gas torch welding was seldom used to weld sheetmetal, since warpage was a byproduct besides the excess heat.
Automotive body repair methods at the time were crude and yielded improprieties until MIG welding became the industry standard. Since the s, when high strength steel became the standard for automotive manufacturing, Cutting a rail just before renewing the rails and the ballast.
After the s, the oxyacetylene torch fell out of use for sheet- Cutting is initiated by heating the edge or leading face metal welding in the industrialized world. A cutting torch in the ferrous material to oxidize the iron quickly into has a or degree angled head with ori ces placed molten iron oxide, producing the cut. Initiating a cut in around a central jet. The outer jets are for preheat ames the middle of a workpiece is known as piercing.
The central jet carries only It is worth noting several things at this point: oxygen for cutting. Oxygen lances the direction of the cut, as well as giving a better preheat and other custom made torches do not have a sepa- balance. Or use it to find and download high-quality how-to PowerPoint ppt presentations with illustrated or animated slides that will teach you how to do something new, also for free. Or use it to upload your own PowerPoint slides so you can share them with your teachers, class, students, bosses, employees, customers, potential investors or the world.
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