Background
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The first cast of duplex was made at Avesta in Sweden in 1930 when the idea of duplex stainless steels were subjected to discuss within industries. During last 30 years the duplex steels have been remarkably evolved and used in a significant way. The evolution in steel making techniques affected mainly to this take off.
Duplex stainless steels is a combination of many of the beneficial properties of ferritic and austenitic steels. First duplex steel grades had a great performance characteristics as well as limitations. The metallurgical processes at that time were not suitable for producing grades with the right austenite-ferrite balance. These early duplex steels were also high in carbon content because of the unavailability of efficient decarburization techniques. Because of these limitations the products using this materials were limited to specific applications. (Alvares-Armas, 2008)
Advancement of processing techniques in late 1960s and early 1970s led to the fabrication of modern duplex steels. Introduction of vacuum and argon oxygen decarburization (VOD and AOD) was the main factor that led to this massive development in duplex steels during this period. By the advancement of these techniques it was possible to achieve steels with low carbon content mixing with high nitrogen and chromium contents in balance with austenite and ferrite. This eliminated lot of shortcomings in old duplex steels. The alloy content provided a resistant to corrosion while duplex microstructure contributed to prevent chloride stress cracking under severe conditions. And these duplex steels possessed good weld ability also.
Modern duplexes were used for offshore and near shore industries where conditions are severe and ...
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... cutting which uses a flame-fired torch using oxygen and propane in conjunction with iron powder is also used to cut steel. This method is clean and fast. Plasma jet cutting, is another method that uses an ionized gas column in conjunction with an electric arc through a small orifice. The gas produces extremely high temperatures to melt the metal. (Chater, 2010)
Finishing
Finally the surface is finished to the required standard by using several methods.
Finish type Method
Dull finish Hot rolling, annealing, and descaling
Bright finish First hot rolling and then cold rolling on polished rolls
Highly reflective finish Cold rolling in combination with annealing in a controlled atmosphere furnace, by grinding with abrasives, or by buffing a finely ground surface
Mirror finish Polishing with progressively finer abrasives, followed by extensive buffing
-Developed and implemented strip casting overseas to eliminate a step in the steel making process
The extraordinary power of the steel industry to shape the life of its communities and the people in them remain...
The beginnings of modern processing of iron can be traced back to central Europe in the mid-14th century BC. Pure iron has limited use in today’s world. Commercial iron always contains small amounts of carbon and other impurities that change its physical properties, which are much improved by the further addition of carbon and other alloying elements. This helps to prevent oxidation, also known as rust.
To begin, evidence of steel goes back 4,000 years, but not until the late 1800s did the steel age begin. Iron was Steel was not mass produced until the Bessemer Process was created. The Bessemer Process is when the extra carbon in molten pig iron is removed by oxidation. “Not only did the Bessemer Process impact the society of the time but also sent ripples throughout the years.”(From
Stainless steel is an alloy of steel and chromium, molybdenum, nickel, carbon, aluminium and silicon. Basic steel contains iron and carbon before being transformed into stainless steel. Chromium, though is what make stainless steel rust resistant. Stainless steel is harder than brass to form into various shapes and this makes the tapware and mixers that contain a bit more expensive than those with solid brass construction. As with brass, stainless steel resist corrosion, rust and stains.
Reese, C.D. and Eidson, J.V. (1999). Handbook of OSHA construction safety and health. Boca Raton, FL. CRC Press
This report will focus mainly on the casting processes used. Casting Processes The most common process of constructing alloy wheels is One-Piece Casting, there are a number of methods to do this, and the most basic is Die Casting, this process is used world wide throughout the casting industry and is not exclusive to alloy wheels. The Die Casting process uses a permanent mould usually made of metal, which generally means that there is high tooling costs compared to other methods of casting, but this high tooling cost is combined with low production costs. This means that die casting is suitable for products with a large production number. There are four main processes in the die casting family, these are: Gravity Die Casting Pressure Die Casting Low Pressure Die Casting Squeeze Casting Gravity Die Casting
Stainless steel is a type of alloy that has a very strong lattice structure (an arrangement/ shape of the crystals or other objects) which in some case can be more beneficial than others depending on the type of application it may be used for. In many cases this structure will make the material more suited to being used in engineering applications such as tools for instance a hammer (stainless steel alloys) , also they can be used for gears, engines, electrical motors and hydraulic systems because the structure makes the material so strong. So when the arrangement of the structure is as above it makes the overall material even stronger which makes it a good for all the applications stated above. I believe its strength and durability are its main properties as these are commonly needed in the engineering industry, although it is also very well known to be used for its corrosion resistance as it is resistant to many types of corrosion. It is used for these properties because the components such as gears need to be strong in order to keep transferring and altering the rotary motion and torque exhibited in the machine that it may be used in, durable to withstand any loads or pressure put onto it and also corrosion resistance to give the components a bigger life span and increase its rate of work throughout its required use.
A steel is usually defined as an alloy of iron and carbon with the content between a few hundreds of a percent up to about 2 wt%. Other alloying elements can amount in total to about 5 wt% in low-alloy steels and higher in more highly alloyed steels such as tool steels and stainless steels. Steels can exhibit a wide variety of properties depending on composition as well as the phases and microconstituents present, which in turn depend on the heat treatment.
It is a process for giving a particular image to a pliable raw material by injecting into a mould.It can be performed with a host of materials, including metals, glasses and thermosetting and thermoplastic polymers. For getting the required shape the material is first heated barrel, mixed and injected into a mold cavity where it cools and get harder.Usually the products are made by engineers but the moulds are made by a mould maker from metals like steel or aluminium.Today it is widely being used for manufacturing entire body panels of cars.
In this paper we will explore on the brief manufacturing process of steel containers and some vital issues relating to the production process.
There are trade-off between properties of meterials.People chose materials according to desired properties. They prefered steel to iron and stainless steel to steel. Steel has high tensile strength compare to the iron. Stainless steel has some characteristic features that make it very popular in variety applications. It’s corrosion-resistant, durable and dilutable structure make stainless steel very popular in the structure. For all these reasons, stainless steel is very attractive meterials for variety of applications. By using stainless steel, different shape, colour and forms can be
European countries were not at the same stage of steel production as that of the British. Therefore, their steel productions were not as superior. However, in response to the British, French inventors developed light weight truss known as the Polonceau in 1837. In addition there was the development of forged iron and milled steel. This opened a myriad of opportunities...
Grey cast iron is the most widely used foundry alloy in the world due to its wide range of achievable mechanical properties, good castability, excellent wear resistance and damping properties, high thermal conductivity as well as low cost (20-40% less than steel) (Xu et al., 2005). It is used in such diverse applications as cookware and musical instruments to auto parts and heavy machineries. Microstructure of grey cast iron is characterized by dispersion of graphite flakes in a ferrous matrix. It has been evidently shown that the size, morphology and distribution of graphite flakes greatly affect the physical and mechanical properties of grey cast irons and that these characteristics depend mainly on the chemical composition of the alloy, the foundry practice adapted such as inoculation treatment used and the cooling conditions during solidification (Bartocha et al., 2005; Xu et al., 2005;
Annealing and tempering are not the same types of heat treatment. Annealing can be defined as heating the steel to aus...