properties of iron and steel?

Question

what similarities do they have?/????????????
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Answer 1

Iron is an element.

Steel is an alloy composed mostly of iron with varying amounts of carbon and other components depending on the likely needs.

The similarities are the iron i suppose.

the differences are the strengths,level of brittleness and malleability

Answer 2

There are a lot of similarities between steel and iron. Steel is an alloy of iron along with other elements such as carbon, cobalt, tungsten, chromium, titanium, and other substances.
An alloy is principally a mixture of two or more substances, with limited chemical interaction.
The most important element added to iron to make steel is carbon. Pure iron is fairly weak, but when carbon is added in small amounts(usually under 1% ....since too much carbon causes the product to be brittle and easily damaged) then what results is a far stronger material. Different added substances produce different steels suitable for different purposes.
Some steels are magnetic like iron, others ( such as stainless steel ) are not. By altering the small quantities of substances added to iron, the alloy produced can be made stronger or harder or more ductile or malleable or corrosion resistant than the original iron.

Answer 3

magnetic ones

Answer 4

Basic Properties of Iron
The basic properties of iron include:
Pure iron melts at 1535 degrees C/2795 degrees F
Ordinary (alpha) iron crystals are body-centered cubic (bcc).
770 degrees C is the "magnetic or Curie point," the temperature at which alpha iron becomes magnetic on cooling or loses its magnetism on heating.
At 912 degrees C alpha-iron transforms to gamma-iron (austenite). Austenite crystals are face-centered cubic (fcc).
When heating, at 1400 degrees C/2552 degrees F austenite transforms to delta-iron. Like alpha-iron, delta-iron is bcc.
When cooling, at 1392 degrees C/2538 degrees F delta iron transforms to gamma iron (fcc). This transformation occurs in pure iron only; it is not present in iron-carbon solution.
Steel Manufacture
Steel is made by first refining iron, which includes the removal of impurities and excess amounts of carbon. A specific steel is produced by adding alloying agents, if any, to refined iron that has been adjusted to contain the desired amount of carbon. The process of removing carbon utilizes iron oxide, which must be removed from the molten steel. The iron oxide is dealt with by one of two basic methods: killing and rimming.

Rimmed steels are low carbon steels made by a partially deoxidizing method. Manganese is added in the form of ferromanganese to react with some of the iron oxide, forming FeMn oxide, which is fluid in the molten steel. Aluminum is also used for the same purpose. Nearly pure iron solidifies along the walls of the mold. Carbon monoxide is formed by the reaction of carbon with FeMn oxide, providing bubbles that equalize the shrinkage of the cooling metal. As a result, deep shrinkage "pipes" do not form in rimmed steel. The rimming method is used to make sheets and plates, which make up the largest volume of steel production.
Killed steels are made by adding silicon to molten steel. Silicon reacts with the iron oxide to form silicon oxide (silica, SiO2). Silica is insoluble in the molten steel and floats to the top as slag. Because the oxygen reacts with the silicon, it is not release as a gas. Unlike rimmed steels, the steel does not bubble as it cools, and so is referred to as "killed." Because the rimming method does not work when the carbon content is greater than about 0.15% carbon, the killed steel method is used for high carbon structural and forging steels.
The release of carbon monoxide causes rimmed steels to bubble violently while cooling. Variations on the killing and rimming methods give semi-killed or capped steels, with more controlled bubbling.

Hardening and Softening of Carbon Steel
Steel is iron with up to about 1.7 percent of carbon added. Pure iron cannot be hardened. Iron with less than 0.3% carbon cannot be hardened by heat treatment, but can be work or case hardened. Steel with at least 0.3% carbon can be hardened by heat treatment, as well as by the other methods.
Hardening
Carbon steel is hardened by fast cooling. During very fast cooling, austenite transforms completely to martensite. Martensite consists of highly stressed crystals of austenite containing more carbon than can normally be held at lower temperatures. Due to the fast cooling, the austenite cannot crystalize normally. As a result, the martensite that forms is constrained to a needle-like structure known as an "acicular" formation. Martensite is the basis of all hardened steel.
Annealing
Annealing is the process used to softened carbon steel that has been hardened either by work hardening or heat treatment. Full annealing includes first heating the steel to 100o F. (50o C.) above the critical temperature range, that is, the range of tempertaures in which ferrite transforms to austenite. The exact range varies with the carbon composition of the steel. The steel is held at the annealing temperature for a period of time that depends on the dimensions of the part, and then slowly cooled.

Changes During Annealing
During annealing, austenite transforms to pearlite, which consists of laminar sheets of ferrite and cementite. Chemically, cementite is iron carbide, Fe3C, which is 6.67% carbon by weight.
Low carbon (mild) steel is low in pearlite, high in ferrite (pure iron).
Pearlite increases as carbon content increases toward 0.76% carbon.
Above 0.76% carbon, "free" cementite (outside of pearlite) appears.
The proportion of cementite increases as the carbon content increases to the maximum for steel (~%1.7). (Above this percent age of carbon, the iron/carbon alloy becomes brittle due to the large amount of cementite. Iron with at least this high a percentage of carbon is referred to as cast iron. In practice, commercial cast iron castings typically contain from 2.70 to 3.60% total carbon, which may exist in various forms.)
Pearlite and cementite give the following characteristics:

A high pearlite content gives the steel strength and toughness.
A high cementite content gives a harder steel, with some loss of ductility.
Cryogenic Treatment
Deep cooling used to relieve stresses and increase abrasion resistance of certain alloy steels. The specific purpose of the process is to complete the transformation of austenite to marensite, which is typically incomplete even with the best heat treatment. The austenite than remains after heat treatment is called retained austenite.

The process involves one or more cycles of cooling at -120 to -300o F/ (-84 to -184 o C), typically for several hours. Each cooling cycle is followed, after a return to room temperature by a tempering operation. The tempering is carried out at 300 degrees F (149 degrees C) and serves to stabilize the martensite.

Without cryogenic treatment, the transformation of retained austenite to martensite occurs very slowly over a period of months or even years. Because martensite occupies a larger volume than austenite, this transformation is accompanied by dimensional changes that can cause changes to measuring devices or serious operational problems. For this reason, measuring standards such as gage blocks or parts with a critical fit should be cryogenically treated before being ground to final size. The final grinding also serves to remove a thin surface layer that does not show increased abrasion resistance, exposing the more resistive material underneath.

Classes of Steel
There are three classes of steel based on its carbon composition. These classes are known as the eutectoid, hypoeutectoid, and hypereutectoid compositions.
Eutectoid steels always contain 0.76 percent carbon and consist entirely of a pearlitic structure.
The hypoeutectoid steels contain less then 0.76 percent carbon and have a structure consisting of pearlite surrounded by a ferritic (body cubic centered, bcc) matric. The most widely used steel contains from 0.2 to 0.3 percent carbon. When cooled slowly, this steel has a structure of about 1/3 pearlite and 2/3 ferrite.
The hypereutectoid steels have a carbon content greater than 0.76 percent and consist of pearlite surrounded by a cementite matrix.
As carbon content increases, the size of the ferrite network in hypoeutectoid steels decreases. At 0.76 percent carbon the ferrite network disappears entirely. Above 0.76 percent carbon a cementite network appears. The size of this network increases as the carbon content increases. All other factors being the same, hypoeutectoid steels are softer, more ductile and shock-resistant than hypereutectoid steels, which are harder