Talking about the structure or
framework of a building of course, we already know such as steel and concrete
structures. But one of the most modern framework of today is the use of a steel
frame. So in this discussion, would explain at least the steel construction and
manufacturing as well as its usefulness.
Steel widely used in the manufacture of the structure
or framework of buildings in the form of profile steel, ordinary concrete
steel, woven wire, or on lately in use also in the form of wire pieces called
"fiber" or metal fiber, as reinforcement of concrete. In a smaller scale metal is also widely in use as an amplifier, for example
the shape of nails, screws, bolts, wire, plate, bridge bearings, or as another
form of sheet materials (eg shape of the roof, or floor of the bridge), or also
a form of decoration.
Excess metal as konstuksi material has properties that
are in a better party because it: has a high tensile strength, can be in fox -
fox shape, easy to connect / in welding. Other
properties are: has the price of high electrical conductivity, high thermal
conductivity and can be crushed so shiny a surface. The weakness of most of the metals, especially steel, corrosion resistance
is not due to the influence of air and moisture around and changes shape when
exposed to temperature / high heat. In the
application, as well as metals have high tensile strength, corrosion resistant
pressure or, occasionally also be resistant to shock loads, low temperature,
changing the style or combination, and some other circumstances.
In general, the metal can be divided into two (2) main
types of ferrous metals (ferrous metal), and non-ferrous metals (non-ferrous
metal). Ferrous metals: a metal forming is the main element
iron (fe). Eg cast iron, wrought iron, steel. Nonferrous metals: metallic iron is not the main element. For example: aluminum, copper, tin, gold, etc..
- METAL PRODUCTION
In general, according to the way done at the present
time, there are 4 (four) stages of processing to produce most types of metal,
namely:
- Excavation metal ores
In extracting the ore, there are generally two ways:
Mining and Mining open closed / mining below ground level.
- Preparation of metal ores
In the process of preparation of iron ore / metal,
crushed ore, some impurities contained in the ore disposed of by using the
method of separation wearing heavy equipment. Preparation
of ore also include burning or calcination processes, for example in the
sulfide ore containing compounds, burning to remove sulfur from iron ores
containing carbonate compounds.
- Ore separation metal
The separation is done with the extraction, ie the
process through a chemical process to obtain the metal. There are 2 kinds of extraction process, namely:
1. Process Pirometalurgy. Ore is heated in the blast furnace (blast furnaces) or echo so melt
furnace, then the separation of the molten metal to get it.
2. Elektrometalurgy process. Ore metal separated by means of
melting in an electric furnace or electric electro process.
- Refining and processing of metals.
Metal extraction results are generally still contain
objects or other elements, so it is necessary to further separation. The process of refining and processing is done by oxidation with the heat
in the furnace, melting, distillation (zinc), electrolysis (copper) or by means
of chemical binder (adding Mn into the molten steel).
- Steel Making Process
Steel is an alloy between iron with other elements to
achieve the desired properties. The meaning of the alloy is a
homogeneous solid solution between iron with other elements required. Steel can be processed and mechanically formed into plates, pipes, bars,
profiles, etc..
There are three ways that are often applied in the
steel-making process that can be done by Bessemer Process, Process and Process
Thomas Martin. But the most common way is the Thomas and the Bessemer
process. But both have differences in terms of advantages and
disadvantages. The following comparison or difference between Martin
and Bessemer processes are:
a. Bessemer process:
- Should be drawn from the more pure pig iron, which is not too high especially fosfornya.
- The resulting steel containing low levels of phosphorus.
- Steel contains less oxygen.
- No additional puffs process.
b. Thomas process
A benefit that is:
- Pig Iron less clean can be done.
- Phosphorus can be removed, but if there are only a
portion of phosphorus which in practice does not cause interference.
- Generate additional products such as fertilizers.
- The process is much easier than the Bessemer
process.
The disadvantages are:
- Steel contains more oxygen
- Iron lost more than the Bessemer process (11-13%).
- METAL ALLOY
Steel is iron with a carbon content of less than 2%. Steel can be formed into various shapes according to the needs. Broadly speaking there are two types of steel, namely:
a. Carbon Steel
Also called plain carbon steel carbon steel,
containing mainly carbon elements and a bit of silicon, sulfur and phosphorus. Based on carbon content, carbon steel is divided into:
- Steel with low carbon content (<0.2% C)
- Steel with medium carbon content (0.1% -0.5% C)
- Steel with a high carbon content (> 0.5% C)
Levels of carbon contained in the steel will affect
the tensile strength, hardness and ductility of steel. The higher the carbon content, the tensile strength and hardness of steel
has increased but ductility tends to fall. The use of
steel in the field of civil engineering construction is generally in the form
of steel or steel profiles, steel reinforcement for concrete with a carbon
content of 0.10% - 0.50%. Besides carbon steel is also used for steel / wire
pre-press to carbon s / d 0.90%. In the field
of civil engineering is the most important properties of tensile strength of
the steel itself.
b. Alloy Steel
Steel said in a coherent if the composition of the
alloy elements in particular, instead of plain carbon steel that consists of
elements of silicon and manganese. Alloy steel
gunakan.Unsur more in the most widely used for steel alloys, namely: Cr, Mn,
Si, Ni, W, Mo, Ti, Al, Cu, Nb, Zr.
- CLASSIFICATION OF STEEL
Alloy steel can be classified according to:
Composition
Based on the composition of the alloy steel is divided
into:
- Steel three components: composed of the elements guiding the addition of Fe and C.
- Steel four components: composed of two elements guide ff.
Structure
Steels are
classified based on:
- Pearlite steel
- Martensitic steels
- Steel austensit
- Ferrite steel
- Steel carbide / ledeburit
Steel pearlite (sorbite and trostit), in the can if
the alloying elements is relatively small maximum of 5%, the steel is capable
of in the engine, mechanical properties increased by heat treatments (hardening
and tempering) Steel martensite, elements guides to more than 5% is very hard
and difficult in the machine. Autensit steel, consisting of 10-30%
of certain alloying elements (Mi, Mn, or Co) for example: stainless steel
(stainless stainlees), non-magnetic, and heat resistant steel (heat resistant
steel). Ferrite steel, consisting of a large number of
alloying elements (Cr, W or Si) but low carbon. Can not
harden. Carbide steel (ledeburit), comprising a number of
carbon and carbide-forming elements (Cr, W, Mn, Ti, Zr)
Use
Based on usage and its properties, alloy steels are
classified:
- Steel Construction (structural steel)
- Tool steel (tool steel)
- Steels with special physical properties
Steel construction, differentiated into three groups
depending on the percentage of pemadunya elements, namely:
§ Low alloy steel (maximum 2%)
§ alloy steel intermediate (2-5%)
§ high-alloy steel (more than 5%)
After heat treatments of steel in this type of nature
- the better mechanical properties of plain carbon steel. Tool steel, used for cutting tools, depending on the composition of
materials and objects in thick cut / slice on the cutting speed, working
temperature. Low alloy steel, hardness does not change until the
temperature of 250 c. High alloy steel, hardness does not change until the
temperature of 600 c. Steel with properties - specific physical properties,
can be distinguished as follows:
Stainless steel: 0.1 to 0.45% C; 12-14% Cr.
Heat-resistant steels: 12-14% Cr resistant finite
temperature 750-800 C
15-17% Cr withstand temperatures up to 850-1000 c
Wear resistant steel at high temperatures.
23% Cr, 18-21% Ni, 2-3% Si 13% - 15% Cr, 13-15% Ni 2%
- 5% W, 0.25 to 0.4% Mo, 0.4 to 0, 5% C
- PHYSICAL PROPERTIES AND MECHANICAL STEEL
Properties of steel generally consists of physical
properties and mechanical properties. Physical
properties include: weight, density, thermal conductivity and electrical
conductivity. Steel can be changed in character due to the influence
of load and heat.
Mechanical properties
The mechanical properties of a material is the
material's ability to provide resistance when given the load on the fiber. Or we can say is the strength of the mechanical properties of materials in
the burden that comes from outside. The
mechanical properties of the steel include:
- Strength
Important properties are tensile strength steel. By the time the steel is loaded, it will tend to be deformed steel / change
form. This shape change will cause strain / strain, the
amount of deformation per unit length (ε = ΔL / L). Due to the strain, stress occurs in the steel / stress of, ō
= P / A, where P = load weighing on steel, A = cross-sectional area of steel. At the time the steel is loaded, then there is a stretch. At the time of the initial strain, where the steel is not to change its
shape and when that promote strain load was removed, the steel will return to
its original shape. This strain is called the elastic strain due to the
nature of the material is still elastic. Comparison
between stress with strain in the elastic state is called the "Modulus
of Elasticity / Young's modulus" (E = ō / ε). There are 3 types of stress that occurs in the steel, namely: AP E
- Voltage, where the steel is still in a state of
elastic
- Yield stress, where the steel starts to break down /
melt
- Plastic voltage, maximum voltage steel, where steel
reaches maximum strength.
- Ductility (ductility)
The ability of steel to deform before breaking steel. Tenacity is related to the amount of strain / strain of permanent steel
before breaking. Tenacity is also related to the properties of the
steel can be worked on. How the test a tensile test.
- Violence
Hardness is the resistance of steel to the amount of
force that can penetrate the surface of the steel. How the test with a Brinell hardness, Rockwell, ultrasonic, etc.
- Toughness (toughness)
Toughness is the relationship between the amount of
energy that can be absorbed by the steel until the steel is broken. The smaller the energy absorbed by the steel, the steel is more brittle and
smaller toughness. How the test by means of a sudden blow counts (impact
/ at the notch).
Here's an example of the use of images in the metal building construction.
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| The use of iron as reinforcement in concrete. |
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| The use of steel as a building order. |
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| The use of steel as a building order. |
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| The use of iron as reinforcement in concrete. |
Thus some discussion regarding the manufacturing process and the use of metal on banguanan. may be useful. Thank you.
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