Troostite


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Troostite

 

a structural component of steel and cast iron; a highly dispersed variety of pearlite, namely, a eutectoid mixture of ferrite and cementite.

Troostite was named in honor of the French scientist L. J. Troost (1825–1911). It is formed as a result of the decomposition of austenite at temperatures below 600°C. The interlaminar distance in troostite is less than 0.1 micrometer. Troostite is harder than either pearlite or sorbite. The laminar structure of troostite, with a fan-shaped arrangement of the layers, may be observed using electron microscopy. Dark segments of troostite on a background of light fields of martensite are visible under an optical microscope.

REFERENCES

Guliaev, A. P. Termicheskaia obrabotka stali, 2nd ed. Moscow, 1960.
Bunin, K. P., and A. A. Baranov. Metallografia. Moscow, 1970.
References in periodicals archive ?
On the other hand, cycle time increased to optimize the condition of induction heat treatment avoiding troostite while the bearings with prolonged service life and improved Brinell characteristics were developed.
It can be shown that the troostite (black substance) is precipitated out of the coarse bainite in HAZ, and it gradually diffuses into the BM.
Moreover, the microstructure adjacent to the fusion line shows that the microstructure of the welded zone is relatively finer compared with the BM, and there also exists black granular troostite in the grain boundary of austenite (A).
Fine ferrite precipitates are recorded at the grain boundaries, and the grain itself has a troostite structure.
Presence of all structures of disintegration austenite (pearlite, sorbite, troostite and martensite) in the changed structural condition speaks that this disintegration was preceded with the certain temperature of heating and the speed of cooling caused transformation pearlite in austenite, and then return process of transition of the last in pearlite.
At arsenic steel O8 the layer of mutual crystallization had structure similar with martensite and troostite holidays carbonaceous steel's.
Familiar names associated with the collection include Lewis & Clark, Adam Seybert, Gerard Troost (troostite), Isaac Lea, Henry Seybert (seybertite; son of Adam and discoverer of fluorine and beryllium), Henry Darwin Rogers (first state geologist), Lewis White Williams (williamsite, since discredited as antigorite), Charles Moore Wheatley (owner of the Wheatley mine), William S.
It adjoins a region of incomplete hardening consisting of martensite, troostite, and ferrite.
Allan Young's case of 35 impeccably tasteful thumbnails from Idaho localities, many of them self-collected, was noteworthy, as was Tom Hughes' case which was entirely filled with self-collected things, including a wide, beautiful, baby-blue Silver Bill mine, Arizona rosasite and a terrific thumbnail of willemite ("troostite") from the Sterling Hill mine, New Jersey.