1. What is Iron Ferrite, what is it used for, and where is it found?
Well, a few definitions match your question. First, "ferrite" is the name metallurgists give to the body-centered-cubic phase of iron and its alloys. The 'body-centered-cubic' phrase refers to the way the atoms are arranged in the lattice, to distinguish it from "austenite" which is the face-centered-cubic arrangement. Generally, ferrite is a pretty pure iron- the core iron used in electrical transformers, for example, is ferritic-but there are also some stainless steels that are ferritic. These iron-chromium alloys would have 12 to 18% chromium in them, and used for expensive exhaust systems in automobiles, for example. Iron is not found in nature, as are, say, chunks of copper, but must be refined by a blast furnace or other smelting technique.
2. Which metals do not react with lithium Bromide ad why?
For solving the problem you should have the electro negativity of Li and B and calculate the difference between the two quantities, and for the next step for any metal, you should calculate the difference between its electro negativity and bromine's. Then if the result was higher than first value, one may say that this metal will react with the material otherwise it will not. However, you should have this in mind that the given procedure is true only in standard condition. However, in practice, many other factors will affect. Now I give you the calculations:
Electro negativity for Li = 1
Electro negativity for Br = 1.14
1.14 - 1 = .14
Now we consider a metal, let say Mg. Its Electro negativity is 1.2, so the difference is 1.2-1.14= .06, which is less than .14, so it will not react in standard conditions. Let say Fe, its Electro negativity is 1.8, the difference is 1.8 - 1.14 = .64 which is greater than .14, and it may react and form FeBr2.
3. What is widman statten structure?
Primary Widman statten ferrite either directly grows from the austenite grain surfaces, whereas secondary Widmanst¨atten ferrite develops from any allotriomorphic ferrite that may be present in the microstructure.
Widmanst¨atten ferrite can form at temperatures close to the Ae3 temperature and hence can occur at very low driving forces; the under cooling needed amounts to a free energy change of only 50 J mol. This is much less than required to sustain diffusion less transformation. Because Widmanst¨atten ferrite forms at low under cooling (and above the T0 temperatures),
It is thermodynamically required that the carbon is redistributed during growth.
4. Why duplex or super duplex stainless steels are welded with low heat input type electrode?
Duplex and super duplex stainless steel; but in general it's true for welding of all types of austenitic stainless steels -and you must know that we can assume duplex s. steels as austenitic s. steels cause the amount of austenite is 50% of the matrix equal to ferrite- to use a low heat input process. In addition, the reason is general in austenitic s. steels as well. That is because the weld decays. Austenitic s. steels containing about 0.1% carbon or more are often susceptible to inter granular corrosion in the weld HAZ, which is known as "Weld Decay". In these types of S .Steels the higher the heat input, the more severe the weld decay. However, here is a fact that all duplex stainless steels have a carbon content of less than 0.1%. Therefore, the severity of weld decay may be lighter, but still exists, and sensitization takes place more rapidly as the carbon content is increased.
Porosity is related to air or gas entrapment during the melting or casting process. When the metal cools and solidifies a small hole is left in the casting. Good out gassings of the melt and good foundry practice can eliminate much of this. Porosity can also be caused by lack of flow into the mold, which is a function of the alloy, superheat (temperature above the melting point), complexity of the mold and a few other factors. Another problem might be entrapment of impurities or slag in the melt. This results in a "dirty" casting. Some aluminum alloys can be particularly prone to these problems. Porosity can be eliminated by careful slag control in the melt, filters, and pour techniques.
I am not sure if the problems are particularly Indian versus British but the people who are doing the casting. I have seen excellent Indian, British, U.S., and Mexican castings as well as bad ones for these nations.
Clearly, you have some specific alloy issues possibly relating to an engineering or design problem you are working on. It appears to me then you are seeking some free consultation. I will cover some basics but you need to be talking to a local metallurgical engineer who can help with the specifics of your problem.
First, you mention two different alloys A-479 is a type 405 ferritic alloy, 11.5 - 14.5 Cr, 0.8 C, and no nickel. This single-phase BCC alloy is not heat treatable. The XM-19 alloy is a type 209 austenitic stainless steel, sometimes called Nitronic 50, 20.5 - 23.5 Cr, 0.6 C, 4 - 6 Mn, 11.5 - 13.5 Ni, plus all kinds of minor alloying elements. This stable, single-phase FCC alloy is also not heat treatable but gets its strengthening from cold work.
The primary users of pressure vessels and piping are the chemical, petroleum, and electric power industries. The classification of pressure vessels regarding the material is based on the working environment and service temperature.
For ordinary-temperature service, the ultimate strength of steels remains relatively constant over the temperature range from -30 to 345, consequently the plain carbon steels are the most commercial.
For low-temperature service, to ensure safe performance, the steel must be resistant to the initiation and propagation of a crack under all service conditions. In thick sections, plain carbon steels produced according to fine-grain practice and normalized or quenched and tempered are used for service to -45 degrees centigrade. Low-carbon high nickel steels are used for service down to -195. Austenitic chromium-nickel steels, aluminum, and special copper and aluminum-base alloys have been found to be particularly suitable for applications close to absolute zero. Because austenitic steels have a face-centered cubic (FCC) crystal structure, they retain toughness to very low temperature.
8. What is the different between ferrite percentage and ferrite number?
Ferrite Number is an arbitrary standardized value designating the ferrite content of an austenitic stainless steel weld metal. It should be used in place of percent ferrite or volume percent ferrite on a direct replacement basis.
FN has been adopted as a relative measure for quantifying ferritic content using standardized magnetic techniques. The FN approach was developed in order to reduce the large variation in ferrite levels determined on a given specimen when measured using different techniques in different laboratories. FN approximates the "volume percent ferrite" at levels below 8 FN; above this level, deviation occurs.
A number of instruments are commercially available for determining the ferrite content of welds, including the Magne gage, Severn gage, and ferrite scope.
Brass is alloy of copper and zinc, of historical and enduring importance because of its hardness and workability.
However, brass is not magnetic, the basic magnetic elements are Iron, Cobalt and Nickel and their alloys. Then there are the new ceramic materials, which exhibit magnetic capabilities.
10. Why is steel vital in the construction of an aircraft?
In the aircraft business, carbon steels provide the airframe structure, landing gear, and by alloying with nickel, chromium, and other elements it makes up most of the aircraft gas turbine engine materials. Titanium is used in some cases for the aircraft structure because it is less dense but also much more expensive.
Both are austenitic stainless so, yes they can be easily welded but, and this is a big but, they can and are very different animals. You have not provided much information on the 304 and 316 alloys. 304 is a very common alloy that has a very wide range of compositions, this is like asking for a Chevy where you can get either a corvette or a fiesta. 316 is a little closer range of alloys but there are 316L, 316LN, 316F etc.
12. What other events in history might have affected the growth of Metallurgy?
This question demands a deep historical research. Now I can point out the World War II as a historical event that causes a great progress in metallurgy. For example, it was during WWII that Germans started manufacturing single body ships with the help of welding. However, in the cold waters of north the ships cracked and split into to parts and cracks initiated in the welds! In addition, that was when they realized that in cold environments metals tend to be brittle and welding could increase this tendency. It was the beginning of a great progress in welding techniques and mechanical metallurgy.
13. What is the strongest metal?
If there is any specific metal with the highest strength, I got no information about that. Everyday a new high technology material with unique characteristics is introduced. Now, the concentration is on composite materials. I guess the highest strength must belong to a composite material likely with a titanium alloy or as the matrix. Alternatively, maybe a super alloy is the strongest one. I got no more information.
I have been thinking about this overnight but I am not a chemist so I am unsure of the reactions. I do know that the penny gets shiny when you remove oxygen and impurities like sulfur from the surface. So lets reason together on this....The salt breaks down into hydrogen and chlorine in the water and produces a slightly acidic, HCl, solution. This breaks down the copper oxide pretty well. I do know the chlorine works well to clean of the copper oxide, I use "comet cleaner" with chlorine to clean brass. Now the vinegar has an acetic acid, but this is carbon, hydrogen and oxygen and I think that the salt combines with this to form a slightly basic solution and generates CO2. I would be interested in seeing if the vinegar salt solution with water added would improve the cleaning capability.
They are called boundaries because this is where one crystal interacts with another. The lattice structure does not continue across the interface without mismatch. While there is some lattice, interaction or sharing it is not complete and there are many defects associated with the boundaries. The degree of mismatch determines if the boundary is a high angle boundary (lots of mismatch) or a low angle boundary (very little mismatch) A tilt boundary is an example of a low angle boundary. This is also one of the reasons that diffusion along grain boundaries is so much higher then through the bulk crystal.
16. Which method has more procity in cast part? Which method has more strength in cast part?
The sand casting will have more porosity in the final product. The die cast will also have higher strength both because of the lower degree of porosity and because of the finer grain size. While I have not been directly involved in the production of cylinder blocks there are a number of reasons for the preference of die-casting versus sand casting. Die-casting provided a finer finish, greater tolerance, better repeatability, and generally higher quality casting. They used sand casting of the iron blocks and still do in many cases and initially the used this same method for aluminum. However, the lower melting point of aluminum allows them to do the die casting method.
The calculation is so easy if you have the iron-carbon diagram in your mind. Proeutectoid ferrite is ferrite formed before eutectoid transformation. At 0.8 wt% carbon, we got 100% austenite before the transformation and at 0.02wt% carbon, we got 100% ferrite, and between these two values of carbon content, we have different amounts of proeutectoid ferrite.
Considering that, we have x wt% carbon we calculate proeutectoid ferrite using the tie line.
Proeutectoid ferrite amount = (0.8-x)/ (0.8-0.02)*100=45
==> x=0.45 wt%
You can check it with eyes. At the middle of the tie line, we must have 50% austenite, 50% ferrite; and it is at (0.8-0.02)/2=0.38%C.
We have 45% ferrite, which is less than 50% so we are closer to eutectoid point (0.8%C); so the carbon content must be more than 0.38%.
18. Is nickel considered a non-sparking metal?
Monel and nickel form almost identical spark streams. The sparks are small in volume and orange in color. The sparks form wavy streaks with no sparklers.
So is not as bright as sparks of ferrous alloys. Therefore, that is a way to identify nickel and monel.
19. What kind of cleaning substance or treatments keep or help prevent cast iron from rusting?
Cast iron is a mixture of graphite (carbon) flakes in a matrix of steel (iron with carbon in solution). The graphite, which has the shape of corn flakes, does not contribute much to strength. If anything, it makes the cast iron somewhat porous or sponge like. The graphite does makes it easy to machine and has a dampening effect on the cast iron. However, it also makes for a lot of surface area, which allows plenty of air (oxygen) to get to the iron and form rust.
20. What is the difference between Stainless steel and Alloy Steel?
Stainless steels have at least 11 to 12% chromium in the alloy. Why 11 to 12% minimum you might ask? That much is required to provide a continuous layer of protective chromium oxide on the surface. Alloy steel just means that there are additional elements added to the iron-carbon. So to answer your second question; Yes, stainless steels are by definition alloy steels.
Charpy toughness is a measure of the metals ability to resist tearing or to absorb energy during an impact. Generally, we achieve that by altering the microstructure to be more ductile. In the quenched and tempered alloys (steels) for example, that involves tempering to convert the hard brittle martensite to softer more ductile bainite or a ferrite carbide mixture. Therefore, we are making a softer metal; therefore, if it affects another object it would tend to deform more. There would be less damage to the object being struck because the striking object would deform more and distribute its load across more of the surface of the object being struck.
22. What medal conducts heat best?
In physics, thermal conductivity, (showed by the Latin capital of land), is the intensive property of a material which relates its ability to conduct heat.
Thermal conductivity is the quantity of heat, Q, transmitted through a thickness L, in a direction normal to a surface of area A, due to a temperature gradient (delta T), under steady state conditions and when the heat transfer is dependent only on the temperature gradient.
In general, thermal conductivity tracks electrical conductivity metals being good thermal conductors. There are exceptions: the most outstanding is that of diamond, which has a high thermal conductivity, between 1000, and 2600 W/mk, while its electrical conductivity is low.
Due to the consumption of a large amount of fossil energies to purify, ferrous alloys are not environmental. USA has stopped most of its steel mills, and the strategy is to concentrate mills in the developing countries. In non-ferrous alloys, let us consider only the mostly used alloys, which are copper alloys (including copper, brass, and bronze) and aluminum alloys. Because the rest are produced so much less than mentioned alloys that they are not actually a threat to the environment, furthermore, they are mostly extracted during refining Fe, Al, and Cu. Production of Cu and AL involves melting and electrolyzes procedures. However, the energy per kilogram pure Al needs is much higher than even Fe, but the most of the energy is electrical and much cleaner than that used for Fe. For Cu, through pirometallurgy methods a large amount of energy is gained autogenously, i.e. exothermal reactions occurred during copper making process supply a large amount of energy needed, but it involves producing products that are not environment. There are hydrometallurgy methods to produce copper, which are more environment-friendly.
The word ceramic is derived from the Greek word keramikos, "having to do with pottery". The term covers inorganic non-metallic materials whose formation is due to the action of heat. Up until the 1950s or so, the most important of these were the traditional clays, made into pottery, bricks, tiles and the like, along with cements and glass.
Historically, ceramic products have been hard, porous, and brittle. Technical Ceramics can also be classified into three distinct material categories:
Oxides: Alumina, zirconia
Non-oxides: Carbides, borides, nitrides, silicides
Composites: Particulate reinforced combinations of oxides and non-oxides.
Ceramic materials can be crystalline or amorphous. They tend to fracture before any plastic deformation takes place, which results in poor toughness in these materials. Additionally, because these materials tend to be porous, the pores and other microscopic imperfections act as stress concentrators, decreasing the toughness further, and reducing the tensile strength. These combine to give catastrophic failures, as opposed to the normally much more gentle failure modes of metals.
Martensite crystals ideally have planar interfaces with the parent austenite. The preferred crystal planes of the austenite on which the martensite crystals form are designated habit planes, which vary according to alloy composition. In steels, the parent phase is usually austenite with a face-centered cubic (fcc) crystal structure, but the crystal structure of the product phase may be body-centered cubic (bcc). Under special conditions, steels undergo martensitic transformations in which the crystal structure of the product phase reverts to that of the parent. Most medium-carbon and high-carbon steels form martensite with a bct crystal structure, because carbon atoms occupy only one of the three possible sets of octahedral interstitial positions.
Allotropy means the property by which certain elements (like Fe) may exist in more than one crystal structure. Iron exists in two allotropic forms: BCC and FCC. In other words at 700°C (1290°F) it undergoes an allotropic transformation from FCC to BCC (in quenching, i.e. iron has FCC structure above this temperature and BCC structure below that).
26. Which is stronger, Tungsten or Titanium?
Tungsten has high tensile strength and good creep resistance. At temperatures above 2205 OC (4000 OF), tungsten has twice the tensile strength of the strongest tantalum alloys and is only 10% denser. However, its high density, poor low-temperature ductility, and strong reactivity in air limit its usefulness. Maximum service temperatures for tungsten range from 1925 to 2480 "C (3500 to 4500 OF), but surface protection is required for use in air at these temperatures.
Wrought tungsten (as cold worked) has high strength, directional mechanical properties, and some room-temperature toughness. However, re crystallization occurs rapidly above 1370 "C (2500 OF) and produces a grain structure that is crack sensitive at all temperatures.
27. What is a silver and deming drill bit?
Silver and Denim is the name of a manufacturing company. This company could trace its history back to 1854, although the "Silver & Deming" name does not date back that far. The titular heads were Albert R. Silver and John Deming. Silver & Deming made a variety of machines that were primarily aimed at wheelwrights: hob-boxing machines, spoke-tenoning machines, etc.
Silver & Deming apparently invented the large-size twist drill bit with a turned-down shaft so they can be used in a chuck smaller than the bit's cutting diameter. They did not patent this idea, so the idea was quickly copied by others, but these bits are still called "Silver & Deming drills".
28. How much gold is in a troy ounce?
Troy ounce defined by the troy system of mass. In troy weight, there are 12 ounces in a pound, and a troy pound is 5760 grains (about 373.24 g), rather than 7000 (about 453.59 g). Note: at roughly 31.10 g, the troy ounce is about 10 per cent more than the more-common avoirdupois ounce. These troy ounces are now used only when weighing precious metals like gold and silver. One ounce of gold is always 31.1 g.
29. How to calculate heat affected zone in weld?
Heat affected zone is measured regarding the microstructure changes in the weld. For example in steels, this is the area around the weld zone, which has undergone a transformation. In other words, this is the area, which had been austenitized. For calculating the HAZ after welding, for steels, it is better to macroetech the section of the weld HAZ can be easily recognized by the contrast it makes with the base metal and the weld metal.
30. Why is it so hard to find literature on the wear resistance of titanium?
Titanium in elemental form is so soft it does not even register on a Rockwell C scale. With that being said, I would guarantee that you are using a titanium alloy of some type, most likely a Titanium-Aluminum-Vanadium alloy. These types of alloys can be processed to hardness in the low 40's HRC. In terms of concentrating on wear resistance, hardness is what you are going to want to focus on. I looked in one of my books and found the mechanical properties for various titanium alloys. The book, which you may be interested in purchasing a copy of, has all of the different properties of many materials, including entire chapters on titanium and titanium alloys. Below is the Amazon link to purchasing this book.
31. Is it possible to use metallurgical inverted microscope to other designation?
A microscope is a microscope for most purposes. First, make sure the light source on the scope is useful in seeing whatever it is you want to see. Certain items are seen well in certain lights. The second thing, as I am sure you have already realized, is that you will have a tough time determining where on the sample you are looking, as it is up side down. For this reason, I even prefer a non-inverted scope even for metallurgical tasks. In summary, if you are ok with the sample being upside down, and the light source is sufficient, there is no reason it will not work to the magnification that scope is specified.
A centrifugal system would certainly separate the mercury assuming you could maintain a fluidized bed and that there were not large differences in the sizes of the particles in the slurry. Depending on the volume involved, a vibratory table might be better. There are many other methods, but I would need to know the relative size / volume / solid-liquid ratio information in order to make a useful recommendation. You need to take special precautions in any case to preclude the release of mercury into the environment. This is very east to do I can help you there as well if you care to divulge the nature of your processing circuit.
Aluminum, while it is incredible for some applications due to it being lightweight, is a very soft and weak metal. There really is not any way to get it any where near the hardness of steel. What people are doing for applications requiring lightweight, but strong materials is going with some new age alloys, mostly consisting of titanium and nickel.
Stress relieving of alloy steels (like 4130) has no temperature outlined in the spec of the material. However, it is common practice to stress relieve 4130 between 1050 and 1200 F. This is high enough to relieve the stress with out being hot enough that the material has an austenitic phase change, which occurs around 1350 F.
35. What are Metallurgical microscopes?
A metallurgical microscope is an inverted scope with light sources designed for magnifying structures of metallographically prepared specimens. The magnification is no different from most normal upright scopes. Companies including Nikon and Olympus produce the scopes and you will be able to find a plethra of information about the scopes on their websites. I would also consider contacting their sales reps to ask specific technical questions about the scopes.
