Metal sheets are metals formed by an industrial process into flat and thin pieces. Metal sheets are one of the basic forms used in metalworking and can be cut and bent into various shapes. Countless daily objects are made from metal sheets. The thickness can vary significantly; very thin sheets are considered foil or leaf, and pieces thicker than 6 mm (0.25 inches) are considered as plates.
Sheet metal is available in flat or rolled pieces. The roll is formed by running continuous sheet metal through roll slitter.
In most parts of the world, sheet metal thicknesses are consistently specified in millimeters. In the US, the thickness of metal sheets is generally determined by the traditional, non-linear measure known as the gauge. The larger the number of gauges, the thinner the metal. Commonly used metal sheet steel ranges from 30 gauge to about 7 gauge. Gauges differ between iron (iron-based) metals and nonferrous metals such as aluminum or copper; Copper thickness, for example measured in ounces, represents the weight of copper contained within an area of ​​one square foot. Parts made from metal sheets should maintain a uniform thickness for ideal results.
There are many different metals that can be made into sheet metal, such as aluminum, brass, copper, steel, tin, nickel and titanium. For decorative use, some important sheet metals include silver, gold, and platinum (platinum sheet metal is also used as a catalyst.)
Sheet metal is used on the body of cars and trucks (lorry), airplanes and wings, medical tables, roofs for buildings (architecture) and many other applications. Iron sheets of iron and other materials with high magnetic permeability, also known as laminated steel cores, have applications in transformers and electric machines. Historically, the important use of metal sheets is in the armor of plates worn by cavalry, and sheet metal continues to have many decorative uses, including in horse tactics. Sheet metal workers are also known as "lead bashers" (or "tin knockers"), a name derived from a panel stitching hammer when installing a tin roof.
Video Sheet metal
Materials
Stainless Steel
Grade 304 is the most common of the three classes. It offers good corrosion resistance while maintaining its formability and weldability. The available finishes are # 2B, # 3, and # 4. Grade 303 is not available in sheet form.
Grade 316 has higher corrosion resistance and strength at temperatures higher than 304. It is commonly used for pumps, valves, chemical equipment, and marine applications. The available finishes are # 2B, # 3, and # 4.
Grade 410 is a heat-resistant steel that can be processed, but has a corrosion resistance lower than other grades. These are usually used in cutlery. The only thing available is dull.
Grade 430 is a popular class, low cost alternative to the 300 series. It is used when high corrosion resistance is not the main criterion. Common values ​​for appliance products, often with brushed finishes.
Aluminum
Aluminum is also a popular metal used in sheet metal because of its flexibility, variety of options, cost effectiveness, and other properties. The four most common aluminum classes available as sheet metal are 1100-H14, 3003-H14, 5052-H32, and 6061-T6.
Grade 1100-H14 is pure commercial aluminum, highly chemical and weather resistant. This is quite resilient to draw inside and can be welded, but has low power. These are commonly used in chemical processing equipment, light reflectors, and jewelry.
Grade 3003-H14 is stronger than 1100, while maintaining the same formability and low cost. It is corrosion resistant and can be welded. These are often used in seals, spun and drawn parts, mailboxes, cabinets, tanks, and fan blades.
Grade 5052-H32 is much stronger than 3003 while still maintaining good formation capabilities. It maintains high corrosion resistance and welding capability. Common applications include electronic chassis, tank, and pressure vessel.
Grade 6061-T6 is a commonly processed aluminum alloy. It can be welded, corrosion resistant, and stronger than 5052, but can not be formed. It loses some of its power when welded. These are used in modern aircraft structures.
Brass
In hydroforming sheets, variations in the incoming roll sheet properties are a common problem for the forming process, especially with materials for automotive applications. Although rolls of incoming sheets can meet tensile test specifications, high rejection rates are often observed in production due to inconsistent material behavior. Thus there is a strong need for discriminatory methods to test the formability of incoming sheet materials. The hydraulic sheet bulge test emulates the biaxial deformation conditions commonly seen in production operations.
To Establish a Boundary Curve (FLCs) of Aluminum, Lightweight and Brass. Theoretical analysis is carried out by deriving the regulatory equation to determine Equivalentstress and Equivalent pressure based on bubbles to be round and the results of Contresca criteria with associated flow rules. For the Grid Circular Analysis experiment used.
Investigation of Limits on the Establishment of Various Material Sheets Using Hydraulic Bulk Testing Using Analytical, Experimental and FEA Techniques. Available from: https://www.researchgate.net/publication/321168677_Investigation_of_Forming_Limit_Curves_of_Various_Sheet_Materials_Using_Hydraulic_Bulge_Testing_With_Analytical_Experimental_and_FEA_Techniques.
Maps Sheet metal
Gauge
Use of measuring numbers to establish sheet metal thickness is not recommended by a number of international standards organizations. For example, ASTM states in the ASTM A480-10a specification: "The use of a measuring number is not suggested as an ancient term of limited utility that has no general agreement on meaning."
The manufacturer's standard gauge for Sheet Steel is based on an average weight of 41.82 pounds (18.96 kg) per square foot per inch thick. Gauges are defined differently for iron (iron-based) and non-ferrous metals (eg aluminum and brass).
Tolerance
During the rolling process, the roller bends slightly, resulting in a thinner sheet at the edges. Tolerances in tables and appendices reflect current manufacturing practices and commercial standards and do not represent the Producer Standards Manufacturer, which lacks inherent tolerance.
Formation process
Bending
The equation for estimating the maximum bending strength is,
,
where k is a factor that takes into account several parameters including friction. T is the main tensile strength of the metal. L and t is the length and thickness of the sheet metal, respectively. The W variable is the open width of the V-die or wiping die.
Curling
The curling process is used to form the edge of the ring. This process is used to remove sharp edges. It also increases the moment of inertia near the curved end. The thorns must be rotated away from the dice. This is used to roll material with a certain thickness. Steel tools are generally used because of the amount of wear and tear performed by the operation.
Decambering
This is the metal working process for removing camber, horizontal bend, from strip-shaped material. This can be done on a limited length or coil. This resembles the leveling of the leveling process, but on the edge of the defect.
Images in
Drawing is a forming process in which the metal is stretched over the shape or die. In drawing the depth of the section made more than half its diameter. Deep drawing is used to create automotive fuel tanks, kitchen sinks, two-piece aluminum cans, etc. Images are generally done in several steps called image reduction. The deeper, the more abatement required. Deep drawing can also be done with less reduction by heating the workpiece, for example in the manufacture of sinks.
In many cases, the material is rolled in the factory in both directions to aid in drawing. This leads to a more uniform grain structure that limits tearing and is called "quality-pulling" material.
Expand
Extending is the process of cutting or stamping the gaps in alternating patterns such as the stretcher bonds in the brick and then stretching the sheet open in an accordion mode. These are used in applications where air and water flow are desired as well as when light is desired at a solid flat surface charge. A similar process is used on other materials such as paper to make cheap packaging paper with better properties than flat paper.
Hemming and seaming
Hemming is the process of folding the tip of the sheet metal onto itself to strengthen that edge.
Seaming is the process of folding two metal sheets together to form a connection.
Hydroforming
Hydroforming is a process analogous to deep drawing, in which parts are formed by stretching blanks over stationary dies. The required force is produced by direct application of very high hydrostatic pressure to the workpiece or to the bladder in contact with the workpiece, not by moving parts of the die in a mechanical or hydraulic press. Unlike deep drawing, hydroforming usually does not involve image reduction - these pieces are formed in one step.
Creating additional sheets
Incremental sheet forming or ISF formation process is essentially a working process of sheet metal or sheet forming process. In this case, sheets are formed into final shapes by a series of processes in which small incremental deformations can be performed in each series.
Iron
Iron is a sheet metal process or a sheet metal forming process. It uniformly attenuates the workpiece in a certain area. This is a very useful process. It is used to produce uniform wall thickness parts with a high-to-high diameter ratio. It is used in the manufacture of aluminum beverage cans.
Laser cutting
Metal sheets can be cut in various ways, from hand tools called lead, snip to enormous scissors. With technological advances, sheet metal cutting has switched to the computer for proper cuts. Many cut sheet metal operations are based on numerically controlled computers (CNC) laser cutting or CNC multi-tool blow tool.
The CNC laser involves moving the lens assembly carrying a laser beam over a metal surface. Oxygen, nitrogen or air is fed through the same nozzle from which the laser light comes out. The metal is heated and burned by a laser beam, cutting the sheet metal. The edge quality can be a smooth mirror and a precision of about 0.1 mm (0.0039 in) can be obtained. Cutting speeds on thin sheets of 1.2 mm (0.047 inches) can be as high as 25 m (82 ft) per minute. Most laser cutting systems use CO2-based laser sources with a wavelength of about 10 Âμm; some newer systems use YAG-based lasers with a wavelength of about 1 Âμm.
Photochemical machining
The photochemical machine, also known as etching photographs, is a tightly controlled corrosion process used to produce complex metal parts of sheet metal with very fine detail. The photo-etching process involves light-sensitive polymers applied to raw metal sheets. Using CAD photo tools designed as stencils, these metals are exposed to UV light to leave a design pattern, developed and carved from sheet metal.
Perforating
Perforating is a cutting process that presses several adjacent small holes in a flat workpiece. Perforated metal sheets are used to make various surface cutting tools, such as surform.
Press brake form
This is a bending shape which is used to produce long and thin pieces of metal sheet. The machine that bends the metal is called the press brake. The bottom of the press contains a V-shaped groove called the dice. The top of the press contains a punch that presses the sheet metal into v die, causing it to bend. There are several techniques used, but the most common modern method is "air flexibility". Here, the dice has a sharper angle than the required bend (usually 85 degrees for 90 degree bends) and the top tool is precisely controlled in scratches to push the metal down the amount required to bend it to 90 degrees. Typically, general purpose machines have available bending strengths of about 25 tonnes per meter in length. The width of the dice bottom is usually 8 to 10 times the bent metal thickness (for example, 5 mm material can be bent in 40 mm). The inner radius of the bend formed in metal is not determined by the radius of the upper tool, but with a lower print width. Usually, the inner radius is equal to 1/6 of the width of V used in the forming process.
The press usually has some sort of measure back to the depth of the bend along the work piece. Backgauge can be computer controlled to allow operators to make a series of bends in components for a high degree of accuracy. The simple machine only controls the backstop, the more sophisticated machine controls the position and stop angle, its height and the second position of the reference bench used to search for material. The machine can also record the exact position and pressure required for each bending operation to allow the operator to reach a perfect 90 degree bend in the various operations in that section.
The image shown is air bending. Press brake bending is a different machine. But similar.
Punching
Punching is done by placing a metal stock sheet between the punch and die mounted on the media. The blows and dies are made of hardened steel and have the same shape. The punch is very fitting in size with the dice. The press pushed the punches against and into the dice with enough force to cut the hole in stock. In some cases, blow and die "nest" together to create depression on the stock. In progressive stamping, stock rolls are fed to long/die-punch sets with many stages. Some simple shaped holes can be produced in one stage, but complex holes are made in several stages. In the last stage, the section is released free of "web".
A typical CNC Turret has a choice of up to 60 tools in a rotatable "turret" to bring any tool into a punching position. Simple shapes (eg square, circle, or hexagon) are cut directly from the sheet. The complex shape can be cut by making many square or round pieces around it. The blows are less flexible than the laser to cut the compound shape, but faster for repetitive shapes (eg, air conditioning grille units). CNC blows can reach 600 times per minute.
Typical components (such as the side of computer case) can be cut with high precision from blank sheets in less than 15 seconds either by press or laser CNC machines..
Scroll form
Continuous bending operation to produce open profiles or weld tubes of long length or in bulk.
Scrolling
Rolling is the process of metal or metal forming. In this method, the stock passes one or more pair of coils to reduce the thickness. This is used to create a uniform thickness. These are classified according to their winding temperature.
1.Hot scrolling: in this temperature above recrystallization temperature.
2. Cold rolling: At this temperature the recrystallization temperature is below.
3. Warm windings: At this temperature it is used between hot winding and cold winding.
Spinning
Spinning is used to make tubular parts (axis-symmetric) by fixing a piece of sheet stock to a rotary shape (mandrel). The roll or rigid tool presses the stock against the shape, stretching it until the stock takes shape. Spinning is used to make rocket sleeves, missile nose cones, satellite dishes and metal kitchen funnel.
Stamping
Stamping includes various operations such as punching, blanking, embossing, bending, flanging, and coining; simple or complex forms can be formed at high production levels; tooling and equipment costs can be high, but labor costs are low.
Alternatively, techniques related to repoussÃÆ'Â © and chase have low tooling and equipment costs, but high labor costs.
Water jet cut
Water jet cutter, also known as waterjet, is a device capable of controlling controlled erosion into metals or other materials using water jets at high speed and pressure, or a mixture of water and abrasive substances.
Glide
The process of using an English wheel is called wheeling. This is essentially a process of metalworking or metal formation. The English wheel is used by craftsmen to form a compound curve of flat metal sheets of aluminum or steel. It's expensive, because highly skilled workforce is needed. This can produce different panels with the same method. Press stamping is used for high numbers in production.
Fasteners
Commonly used fasteners on sheet metal include:
- Clecos
- Rivets
- Sheet metal screws
See also
- Grid analysis circle
- Galvanized corrugated iron, also known as Corrugated Sheet Metal
- Diamond Plates
- Form a boundary chart
- Strip Steel
- Temper mill
References
Bibliography
- Oberg, Erik; Jones, Franklin D. (2004). Machine Handbook (edition 27). New York: Press Industry. ISBNÃ, 0-8311-2700-7.
- Parker (2013). Building Victory: Aircraft Manufacturing in Los Angeles Area in World War II . Cypress, CA. ISBN 978-0-9897906-0-4.
External links
- "Production Standard Measurement History". Steel Market Update.
- "Steel Sheet Gauge and Thickness" (PDF) . Fact Sheet Steel . Canadian Sheet Steel Building Institute. April 2009.
Source of the article : Wikipedia
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