In response to the weakness of ferro casting, British Case Iron Research Association in 1948 mixed the alloying cerium, nickel and other alloying elements to cast iron, thus resulting in nodular cast iron. Since then, a number of testing on iron cast emerges in order to result in a better quality, one of which is by adding magnesium to cast iron. Based on the result of the metallographic testing, the addition of the magnesium to the cast iron could result in nodular graphite. It is found that the nodular graphite in cast iron based on a laboratory test, in fact, had the twofold tensile strength closer to the carbon steel. This finding then was patented in 1949 in USA as a year of Nodular Cast Iron (NCI) [1,2].
The graphite in nodular cast iron occupies 10-15% of total volume of materials and is evenly spread in the basic structure (matrix) resembling to the carbon steel. Hence, the mechanical properties of nodular cast iron can be directly correlated to the tensile strength and ductility of the matrix it owns as occurred in carbon steel. However, as the structure of nodular cast iron also contains graphite, the tensile strength, elasticity modulus and impact tenacity proportionally will be lower than the carbon steel, in this case, with an equal matrix. The matrix of nodular cast iron is varied started from the soft and ductile structure of ferrite to the harder and strong structure of pearlite and even to the structures that can only be reached through the addition of alloying materials or through the heat treatment such as martensite and bainit [2, 3].
Bish (2009) conducted a study on the effects of single-step austempering heat treatment and the addition of alloying copper of NCI to the hardness, tensile strength. The study w...
... middle of paper ...
...uctile Iron. Thesis Master of Technology. Rourkela
[6] Hayrynen KathyL., (2002) The Production of Austempered Ductile Iron (ADI), World Conference on ADI.
[7] Sheikh, M. A. (2008) Effect of Heat Treatment and Alloying element on Characteristic of Austempered Ductile Iron. Thesis of Doctor Philosophy. Pakistan: Lahore
[8] Ravishankar, K.S., Rajundra, V., Prosanda, R. (2008). Development of Austempered Ductile Iron for High Tensile and Fracture Toughness by Two Step Austempering Process. World Foundry Congress. 7. P. 35-40
[9] Yang, J., Putatunda, S.K. (2005). Near threshold Fatigue Crack Growth Behavior of Austempered Ductile Cast Iron (ADI) Processed by a Novel Two Step Austempering Process. J. Material Science and Engineering. P. 254-268
[10] Ritha U.,RaoPrasad P. (2009).Study of wear behavior of austempered ductile iron; Journal of Material Science,44,P.1082-1093.
We use metals to construct all kinds of structures, from bridges to skyscrapers to elevators. The strength as well as durability of materials that are crafted out of metal make the materials ideal not only for construction but also for many other applications.
Fatigue failure can be divided in three parts i.e. Crack initiation, Crack propagation and Final rupture.
The machinability of copper and copper alloys is improved by lead, sulfur, tellurium, and zinc while it deteriorates when tin and iron are added. Lead in brass alloys with concentrations around 2 wt%, improves machinability by acting as a microscopic chip breaker, and tool lubricant, while they increase the brittleness of the alloy [17]. Lead additions are used to improve machinability. The lead is insoluble in the solid brass and segregates as small globules that help the swarf to break up in to small pieces and may also help to lubricate the cutting tool action. The addition of lead is however, affect cold ductility which may control both the way in which material is produced and the extent to which it can be post-formed after machining
Solid working execution all around the period, the moderately constrained effect of the wet season and the proceeded slope up of Jimblebar underpinned record handling at Western Australia Iron Mineral of 163 million tons (100% support). Full-year handling direction has been raised by a further five million tons to 217 million tons (100% supports) (BHP Billiton Review, 2014).
Aluminum is a lightweight, silvery metal. The atomic weight of aluminum is 26.9815; the element melts at 660° C (1220° F), boils at 2467° C (4473° F), and has a specific gravity of 2.7. Aluminum is a strongly electropositive metal and extremely reactive. In contact with air, aluminum rapidly becomes covered with a tough, transparent layer of aluminum oxide that resists further corrosive action. For this reason, materials made of aluminum do not tarnish or rust. The metal reduces many other metallic compounds to their base metals. For example, when thermite (a mixture of powdered iron oxide and aluminum) is heated, the aluminum rapidly removes the oxygen from the iron; the heat of the reaction is sufficient to melt the iron. This phenomenon is used in the thermite process for welding iron .
-Developed and implemented strip casting overseas to eliminate a step in the steel making process
INCONEL (nickel-chromium-iron) alloy 600 is a standard engineering material for applications which require resistance to corrosion and heat. The high nickel content gives the alloy resistance to corrosion by many organic and inorganic compounds and also makes it virtually immune to chloride-ion stress-corrosion cracking. Chromium confers resistance to sulfur compounds and also provides resistance to oxidizing conditions at high temperatures or in corrosive solutions. The composition of Inconel 600 is listed in Table
Since all metals have different densities and makeups I think that the heat capacity will greatly vary. The makeup of iron is very different than aluminum so the heat capacity will be quite different. Also, a lot of metals are not completely pure and that will also have some effect on the heat capacity.
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.
The micro hardness of the prepared samples were obtained by using a Vickers Micro hardness Tester (Model : Leco LV 700, USA). 5 readings were taken for each sample to calculate the average hardness. An indentation load of 5gf was used. After calculating the average hardness for each sample, mean variance and standard deviation (S.D.) was calculated to check the consistency of the data.
The basis for the understanding of the heat treatment of steels is the Fe-C phase diagram. Because it is well explained in earlier volumes of Metals Handbook and in many elementary textbooks, the stable iron-graphite diagram and the metastable Fe-Fe3 C diagram. The stable condition usually takes a very long time to develop, especially in the low-temperature and low-carbon range, and therefore the metastable diagram is of more interest. The Fe-C diagram shows which phases are to be expected at equilibrium for different combinations of carbon concentration and temperature. We distinguish at the low-carbon and ferrite, which can at most dissolve 0.028 wt% C at 727 oC and austenite which can dissolve 2.11 wt% C at 1148 oC. At the carbon-rich side we find cementite. Of less interest, except for highly alloyed steels, is the d-ferrite existing at the highest temperatures. Between the single-phase fields are found regions with mixtures of two phases, such as ferrite + cementite, austenite + cementite, and ferrite + austenite. At the highest temperatures, the liquid phase field can be found and below this are the two phase fields liquid + austenite, liquid + cementite, and liquid + d-ferrite. In heat treating of steels the liquid phase is always avoided. Some important boundaries at single-phase fields have been given special names. These include: the carbon content at which the minimum austenite temperature is attained is called the eutectoid carbon content. The ferrite-cementite phase mixture of this composition formed during cooling has a characteristic appearance and is called pearlite and can be treated as a microstructural entity or microconstituent. It is an aggregate of alternating ferrite and cementite particles dispersed with a ferrite matrix after extended holding close to A1. The Fe-C diagram is of experimental origin. The knowledge of the thermodynamic principles and modern thermodynamic data now permits very accurate calculations of this diagram.
By adding up to 2%,of carbon it makes the steel tough and strong. Although it’s tough and strong, it is able to bend. To make sure that the metal doesn’t rust, it has a zinc coating on it. Iron is 26 on the periodic table,and considered an “transition metal,” meaning that it is ductile and malleable, and conduct electricity and heat. ... “Some other elements that are similar to iron are cobalt and nickel. They are the only elements known to produce a magnetic field.” Zinc is 30 on the periodic table and it is also a transition metal like iron. “The first iron used by humans is likely to have come from meteorites.” A meteorite is a meteor that survives its passage through the earth's atmosphere such that part of it strikes the ground. More than 90 percent of meteorites are of rock, while the remainder consist wholly or partly of iron and nickel. Meteors are believed to have been from the asteroid belt of Mars and
Aluminum is the most abundant metal and the third most abundant element in the earth's crust, after oxygen and silicon. It makes up about 8% by weight of the earth’s solid surface. Aluminum also chemically reactive to occur naturally as the free metal (Kobayashi et al, 2002). There are many applications of Aluminum in our daily life, such as construction machinery, aircraft construction, ship construction, home furnishing and electronics component. For the vehicle industry, Aluminum has established a worldwide position because of its advantages over the other competitive materials, like light weight, providing exceptional unit strengths (strength/density ratio), high corrosion resistance, low maintenance costs, good temperature resistance (even in arctic environments), ductile, easily joined by all commercial processes such as welding, brazing, or soldering, at the last, aluminum can be easily formed by all common processes, including extrusion (a major advantage) and can be recycled.
Metals possess many unique fundamental properties that make them an ideal material for use in a diverse range of applications. Many common place things know today are made from metals; bridges, utensils, vehicles of all modes of transport, contain some form of metal or metallic compound. Properties such as high tensile strength, high fracture toughness, malleability and availability are just some of the many advantages associated with metals. Metals, accompanied by their many compounds and alloys, similar properties, high and low corrosion levels, and affects, whether negative or positive, are a grand force to be reckoned with.
In summary, the rate of cooling from the austenite phase is the main determinant of final structure and properties.