Search results
Results from the WOW.Com Content Network
Pearlite is a two-phased, lamellar (or layered) structure composed of alternating layers of ferrite (87.5 wt%) and cementite (12.5 wt%) that occurs in some steels and cast irons. During slow cooling of an iron-carbon alloy, pearlite forms by a eutectoid reaction as austenite cools below 723 °C (1,333 °F) (the eutectoid temperature).
Under a light microscope, the microstructure of bainite appears darker than untempered martensite because the bainite has more substructure. [9] The hardness of bainite can be between that of pearlite and untempered martensite in the same steel hardness. The fact that it can be produced during both isothermal or continuous cooling is a big ...
Acicular ferrite is a microstructure of ferrite in steel that is characterised by needle-shaped crystallites or grains when viewed in two dimensions. The grains, actually three-dimensional in shape, have a thin lenticular shape.
Antonie van Leeuwenhoek (1632–1723). The field of microscopy (optical microscopy) dates back to at least the 17th-century.Earlier microscopes, single lens magnifying glasses with limited magnification, date at least as far back as the wide spread use of lenses in eyeglasses in the 13th century [2] but more advanced compound microscopes first appeared in Europe around 1620 [3] [4] The ...
Molar volume vs. pressure for α-Fe at room temperature. The primary phase of low-carbon or mild steel and most cast irons at room temperature is ferromagnetic α-Fe. [8] [9] It has a hardness of approximately 80 Brinell. [10] [11] The maximum solubility of carbon is about 0.02 wt% at 727 °C (1,341 °F) and 0.001% at 0 °C (32 °F). [12]
All pages with titles containing Ferrite; Ferrite bead, a component placed on the end of a data cable to reduce interference; Ferrite core, a structure on which the windings of electric transformers and other wound components are formed; Barium ferrite (BaFe 12 O 19), a ferrimagnetic ceramic material; Bismuth ferrite, a promising multiferroic ...
If the cooling rate is slower than the critical cooling rate, some amount of pearlite will form, starting at the grain boundaries where it will grow into the grains until the M s temperature is reached, then the remaining austenite transforms into martensite at about half the speed of sound in steel.
This increases the brittleness of the steel in a way that can only be relieved by recrystallizing. Widmanstätten structures made from ferrite sometimes occur in carbon steel, if the carbon content is below but near the eutectoid composition (~ 0.8% carbon). This occurs as long needles of ferrite within the pearlite. [16]