HOW does chromium protect steel from corrosion?
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Stainless steel contains chromium that was put there by diffusing it in there with high heat and a concentration difference.  Metals corrode because they get converted from neutral, solid form to ions (they are oxidized, that's why oxidation is a synonym for corrosion) that combine with negatively charged ions (usually oxides or chlorides) and are no longer metal, and many times soluble, hence taking a chunk out of your original metal.  Chromium is a more active metal than the iron that makes up most of the steel.  This means when both are present on the same surface, the chromium is more likely to dissolve into ions and electrons than the iron.\n\nWhen stainless is exposed to dissolved oxygen in water (for example) the chromium atoms will dissolve their way towards the surface of the steel. Then, they will be oxidized:\n\nCr(s)-->Cr3+ + 3e-\n\nWhat little iron that may have been oxidized before the chromium reached the surface can gain these 3 electrons and join the surface as solid iron again.  Otherwise, once the Cr reaches the surface, it'll corrode to form chromium oxide, a greenish black powdery ceramic that doesn't stick well to the surface, and can be easily rinsed away or knocked off.  And while the Cr will be oxidized, the iron will not because the Cr is more active. The steel itself remains shiny and well, stainless (without rust).  However, when the steel runs out of Cr atoms to sacrifice to protect the iron (once they become chromium oxide, they won't go back to being regular Cr metal, and the oxide does NOT stick to the surface to protect it), the iron will rust.
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You dip the metal you want plated into a solution containing ions of the metal you want to plate with, such as chromium (chrome).  The dipped metal is attached to an electrical current, which induces a redox reaction.  The actual chemistry is a little more complicated, but the easy version is that those metal ions become solid metal attached to the electrode (the metal that you dipped in the solution).  The new metal is now permanently bonded to the old metal, and you have a set of chrome rims.
244814
Yes, it does.  This is because the salt provides electrolytes and allows for faster oxidation.  Salt water spray is often the test method used to determine if a given paint offers more corrosion protection than a standard reference paint.  Corrosion inhibitors, like zinc chromate and others, offer protection by  interfering with the oxidation process.
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it prevents the steel from rusting. Zinc rusts too, but more slowly than steel, and it doesn't tend to eat away it's structure. \nZinc coatings prevent oxidation of the protected metal by forming a barrier, and by acting as a sacrificial anode if this barrier is damaged. Zinc oxide is a fine white dust that (in contrast to iron oxide) does not cause a breakdown of the substrate's surface integrity as it is formed. Indeed the zinc oxide, if undisturbed, can act as a barrier to further oxidation, in a way similar to the protection afforded to aluminium and stainless steels by their oxide layers.
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The Iron content in Stainless steel is less than other steel alloy\nThe Cromium Content is more\nCr is not a ferromagnetic matter So Stainless steel is not ferromagnetic
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If you are asking how to reverse the corrosion, you could use an electrical cell to reduce the iron, but the product would not be carbon steel as you originally had.  The best way to deal with corrosion is toprevent it, either through coating or the use of a sacrificial anode depending on your situation.
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Steel is a metal alloy whose major component is iron, with carbon content between 0.02% and 1.7% by weight. Carbon is the most cost effective alloying material for iron, but many other alloying elements are also used.[1] Carbon and other elements act as a hardening agent, preventing dislocations in the iron atom crystal lattice from sliding past one another. Varying the amount of alloying elements and their distribution in the steel controls qualities such as the hardness, elasticity, ductility, and tensile strength of the resulting steel. Steel with increased carbon content can be made harder and stronger than iron, but is also more brittle. The maximum solubility of carbon in iron is 1.7% by weight, occurring at 1130° Celsius; higher concentrations of carbon or lower temperatures will produce cementite which will reduce the material's strength. Alloys with higher carbon content than this are known as cast iron because of their lower melting point. Steel is also to be distinguished from wrought iron with little or no carbon, usually less than 0.035%. It is common today to talk about 'the iron and steel industry' as if it were a single thing; it is today, but historically they were separate products.\n\nSteel is often classified by its carbon content: a high-carbon steel is serviceable for dies and cutting tools because of its great hardness and brittleness.\n\nlow- or medium-carbon steel is used for sheeting and structural forms because of its amenability to welding and tooling. \n\nAlloy steels, now most widely used, contain one or more other elements to give them specific qualities. \nAluminum steel is smooth and has a high tensile strength. \n\nChromium steel finds wide use in automobile and airplane parts on account of its hardness, strength, and elasticity, as does the chromium-vanadium variety. \n\nNickel steel is the most widely used of the alloys; it is nonmagnetic and has the tensile properties of high-carbon steel without the brittleness. \n\nNickel-chromium steel possesses a shock resistant quality that makes it suitable for armor plate. \n\nWolfram (tungsten), molybdenum, and high-manganese steel are other alloys. \n\nStainless steel, which was developed in England, has a high tensile strength and resists abrasion and corrosion because of its high chromium content.
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A metal's corrosion (rusting) rate depends on its chemical properties. Some metals just take longer than others to corrode. Keep in mind that most metals have very high melting temperature, so in general high temperature doesn't contribute to the corrosion of a piece of metal just sitting in a damp space. For temperature to be of concern, it has to be around 700 degrees Celsius.\n\nI don't know much about your experiment, but you might not be using an appropriate metal sample. Most commonly found metals come with coatings or contain chemical inhibitors to prevent corrosion. Think about bikes sitting in outside in a humid (moisture-rich) environment. Manufacturers have to coat the metals to prevent this corrosion, or else no one would buy their product. This is the case with most metals. So if you just picked up something laying around the house and tried to corrode it, your experiment might not be successful. You should also be aware that only ferrous (iron) alloys rust, and the particular metal you tested might be something else.\n\nGo to google and type "rusting metal" (without the "s). The first four sites have lots of info.\n\n*It wouldn't rust in the freezer because there's no moisture in the freezer.
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Sorry, what is LCC?  Low carbon (?)\n\nThe only way to harden a steel alloy material by air cooling is if the alloy content is quite high - this is the reason for adding the alloys.  If you don't have high alloy content, you MUST quench to harden the steel.\n\nYou're going to need a carbon content above 0.3% to see any improvement in properties from quenching.  \n\nAnother heat treatment cycle on steel is case-hardening - this would improve surface hardness.
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Steel is iron that has most of the impurities removed. Steel also has a consistent concentration of carbon throughout (0.5 percent to 1.5 percent). Impurities like silica, phosphorous and sulfur weaken steel tremendously, so they must be eliminated. The advantage of steel over iron is greatly improved strength. \n\nTo answer your qestion, it should be about 95%. \n\nStainless steel contains at leat 10.5 % chromium (about 85% iron)
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Copper, Iron, Chromium, Aluminium
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Chromium has been added, so it is less likely to rust (thus "stainless")
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Most corrosion is on the outside so it really doesn't make a difference, hot or cold. What determines corrosion is the \nenvironment outside of the pipe.
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Chromium is an essential trace mineral that helps the body maintain normal blood sugar levels. Chromium also may play a role in increasing HDL cholesterol (the good kind) while reducing overall cholesterol levels. It has also been linked to reducing body fat and body weight. This chromium is in the picolinate form. (available in the form of capsule 200 mcg/day)\n\nBy\nSURESH KUMAR .M.P.T.,M.I.S.C.P\nCHARTERED PHYSIOTHERAPIST\nskmpt2002@yahoo.co.uk
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Hexavalent chromates have been in use for the purpose of passivating zinc and cadmium plating for over 100 years. Hexavalent based chromates possess many favorable characteristics in addition to increasing the corrosion prevention performance of plated parts. \n\nPrevents Oxide Formation \nProvides Color \nSlows corrosion \nProvides adhesion for organics such as paint \nConductive \nThin \nFlexible \nLubricious \nEasily applied \nStable for weeks or months \nDurable \nResilient (repairs itself)\nWhen the surface of a part is damaged, hexavalent chromates have a unique self-healing property, which means that if scratched the chrome layer will flow back and repassivate the area. \nCoats in recesses \nEasy to strip \nNever the less, the push to replace chromates that use hexavalent chromium is gaining momentum. Hexavalent chromium is considered a hazardous substance (toxic and carcinogenic). There is a growing need to provide an environmentally friendly alternative.\n\nHowever, not all forms of chromium are hazardous to humans. Trivalent Chromium (CrIII) is actually an essential nutrient that aids the body to use sugars, proteins and fat. An intake of 50 to 200 µg per day is recommended for adults.
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Chromium is added to the steel. This actually provides a hard oxidation layer. So basically, there is already a layer of oxide (kinda like rust), but it doesn't flake off like the redish type rust you might see on your car. This layer actually protects the rest of the material, by keeping other impurities from reacting with the interior (or exterior).
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Iron is stronger and steel of course is stronger still.  Further, iron corrodes only if not cared for.  Copper will form a patina over time even if cared for.