The carbon absorbed by the iron does not take on a graphitic form, however, as in the case of cast iron, but enters into a chemical compound with the iron, a hard brittle substance called "cementite" by metallurgists.    From Wordnik.com.  [The Working of Steel Annealing, Heat Treating and Hardening of Carbon and Alloy Steel] Reference

However, upon cooling this steel, the carbon again enters into combination with a definite proportion of iron (the carbide "cementite," Fe3C), and accumulates into small crystals which can be seen under a good microscope.    From Wordnik.com.  [The Working of Steel Annealing, Heat Treating and Hardening of Carbon and Alloy Steel] Reference

When cooled slowly below 670 degrees, martensite yields a heterogeneous mixture of pearlite and ferrite (or cementite, if the original mixture contained between 0.8 per cent. and two per cent. of carbon).    From Wordnik.com.  [Popular Science Monthly Oct, Nov, Dec, 1915 — Volume 86] Reference

One of these is pure iron, and the other is pure cementite.    From Wordnik.com.  [The Working of Steel Annealing, Heat Treating and Hardening of Carbon and Alloy Steel] Reference

Austenite has been defined as a solid solution of cementite (Fe3C) in gamma iron.    From Wordnik.com.  [The Working of Steel Annealing, Heat Treating and Hardening of Carbon and Alloy Steel] Reference

Martensite is usually considered to be a solid solution of cementite in beta iron.    From Wordnik.com.  [The Working of Steel Annealing, Heat Treating and Hardening of Carbon and Alloy Steel] Reference

The dark grains are pearlite, separated by white films of iron carbide (cementite).    From Wordnik.com.  [The Working of Steel Annealing, Heat Treating and Hardening of Carbon and Alloy Steel] Reference

Higher carbon steels show films of cementite outlining grains of pearlite (Fig. 48).    From Wordnik.com.  [The Working of Steel Annealing, Heat Treating and Hardening of Carbon and Alloy Steel] Reference

It is possible to change the relative sizes of the ferrite and cementite crystals by heat treatment.    From Wordnik.com.  [The Working of Steel Annealing, Heat Treating and Hardening of Carbon and Alloy Steel] Reference

From this combination, we are able to get a very strong ferrite matrix and a very hard tough cementite.    From Wordnik.com.  [The Working of Steel Annealing, Heat Treating and Hardening of Carbon and Alloy Steel] Reference

Apparently the quick cooling prevents the normal change back to definite and sizeable crystals of ferrite and cementite.    From Wordnik.com.  [The Working of Steel Annealing, Heat Treating and Hardening of Carbon and Alloy Steel] Reference

Pearlite is a definite conglomerate of ferrite and cementite containing about six parts of the former to one of the latter.    From Wordnik.com.  [The Working of Steel Annealing, Heat Treating and Hardening of Carbon and Alloy Steel] Reference

A final steel will be composed of pearlite; ferrite and pearlite; or cementite and pearlite, according to the carbon content.    From Wordnik.com.  [The Working of Steel Annealing, Heat Treating and Hardening of Carbon and Alloy Steel] Reference

Chromium when alloyed with steel, has the characteristic function of opposing the disintegration and reconstruction of cementite.    From Wordnik.com.  [The Working of Steel Annealing, Heat Treating and Hardening of Carbon and Alloy Steel] Reference

A quickly quenched carbon steel is mostly martensitic which, as noted, is a solid solution of beta iron and cementite, hard and brittle.    From Wordnik.com.  [The Working of Steel Annealing, Heat Treating and Hardening of Carbon and Alloy Steel] Reference

The cementite, although adding to the tensile strength, is very brittle and the strength of the pearlite is the combination of the ferrite and cementite.    From Wordnik.com.  [The Working of Steel Annealing, Heat Treating and Hardening of Carbon and Alloy Steel] Reference

He was particularly interested in the behaviour of short cracks and their interaction with microstructural barriers: grain boundaries, cementite platelets.    From Wordnik.com.  [iMechanica - Comments] Reference

In fact, the difference between the hard, brittle cementite and the soft, greasy graphite, accounts for many of the differences between steel and gray cast iron.    From Wordnik.com.  [The Working of Steel Annealing, Heat Treating and Hardening of Carbon and Alloy Steel] Reference

But we may anticipate by saying that some of the iron unites with all the carbon to form a new substance, very hard, a carbide which has been called "cementite.".    From Wordnik.com.  [The Working of Steel Annealing, Heat Treating and Hardening of Carbon and Alloy Steel] Reference

At that moment, in fact, the ferrite, cementite or pearlite which previously existed has lost its identity by everything going into the solid solution called austenite.    From Wordnik.com.  [The Working of Steel Annealing, Heat Treating and Hardening of Carbon and Alloy Steel] Reference

Definition: A cast iron made by prolonged annealing of white iron in which decarburization, graphitization, or both take place to eliminate some or all of the cementite.    From Wordnik.com. Reference

As more and more carbon is contained in the alloy -- for steel is a true alloy -- it begins to appear as graphite, and its properties counteract the remaining brittle cementite.    From Wordnik.com.  [The Working of Steel Annealing, Heat Treating and Hardening of Carbon and Alloy Steel] Reference

Figure 12.33 The iron-carbon phase diagram showing the relationship between the stable iron-graphite equilibria (solid lines) and the metastable iron-cementite reactions (dashed lines).    From Wordnik.com.  [Recently Uploaded Slideshows] Reference

The growth is continually destroyed by the hammering, which should consequently be continued down to the upper critical temperature when the austenite crystals break up into ferrite and cementite.    From Wordnik.com.  [The Working of Steel Annealing, Heat Treating and Hardening of Carbon and Alloy Steel] Reference

Improving Machinability: Spheroidite - A microconstituent containing coarse spheroidal cementite particles in a matrix of ferrite, permitting excellent machining characteristics in high-carbon steels.    From Wordnik.com.  [Recently Uploaded Slideshows] Reference

Many of the properties of steel, as they vary with carbon content, can be linked up with the increasing amount of this hard carbide cementite, distributed in very fine particles through the softer iron.    From Wordnik.com.  [The Working of Steel Annealing, Heat Treating and Hardening of Carbon and Alloy Steel] Reference

Slide 8: Figure 12.3 Electron micrographs of (a) pearlite, (b) bainite, and (c) tempered martensite, illustrating the differences in cementite size and shape among these three microconstituents ( 7500).    From Wordnik.com.  [Recently Uploaded Slideshows] Reference

Subsequent cooling gives a coarse texture, or an arrangement of ferrite, cementite and pearlite grains which is greatly coarsened, reflecting the condition of the austenite crystals from which they were born.    From Wordnik.com.  [The Working of Steel Annealing, Heat Treating and Hardening of Carbon and Alloy Steel] Reference

Formation of all the cementite has been completed by the time the temperature has fallen to the lower critical, and below that temperature the steel exists as a complex substance of pure iron and the iron carbide.    From Wordnik.com.  [The Working of Steel Annealing, Heat Treating and Hardening of Carbon and Alloy Steel] Reference

It generally proves advisable to have the case contain between 0.90 per cent and 1.10 carbon; more carbon than this gives rise to excess free cementite or carbide of iron, which is detrimental, causing the case to be brittle and apt to chip.    From Wordnik.com.  [The Working of Steel Annealing, Heat Treating and Hardening of Carbon and Alloy Steel] Reference

If the steel be then cooled, the austenite breaks up into new crystals of ferrite, cementite and pearlite; and in general if the temperature has not gone far above the critical, and cooling is not excessively slow, a very fine texture will result.    From Wordnik.com.  [The Working of Steel Annealing, Heat Treating and Hardening of Carbon and Alloy Steel] Reference

In the event of the cementite being strengthened, as in the case of strictly chromium steels, an increased tensile strength is readily obtained without loss of ductility and if the ferrite is strengthened then the tensile strength and ductility of the metal is still further improved.    From Wordnik.com.  [The Working of Steel Annealing, Heat Treating and Hardening of Carbon and Alloy Steel] Reference

cementite is a definite compound of iron and carbon represented by the formula Fe 3 C. When cooled slowly below 670o, martensite yields a heterogeneous mixture of pearlite and ferrite (or cementite, if the original mixture contained between 0.8 per cent. and two per cent. of carbon).    From Wordnik.com.  [The Scientific Monthly, October-December 1915] Reference

A mixture of ultramicroscopic crystals of ferrite (alpha iron) and cementite (Fe3C).    From Wordnik.com.  [The Working of Steel Annealing, Heat Treating and Hardening of Carbon and Alloy Steel] Reference

"I think," said Hoddan, "that we can make an electronic field that'll soften the cementite between the crystals of steel, without heating up anything else.    From Wordnik.com.  [The Pirates of Ersatz] Reference