| 释义 |
pearlite|ˈpɜːlaɪt|
[f. pearl n.1 + -ite1.]
1. Min. Variant form of perlite, = pearl-stone.
2. Metallurgy. One of the forms in which carbon and iron are combined in cast steel: see quots.
1888H. M. Howe in Engin. & Mining Jrnl. 18 Aug. 132 Minerals which compose iron. Name suggested here... Pearlyte. A mixture of about 2/3 ferrite and 1/3 cementite. 1889Nature 14 Nov. 37/2 Prof. Howe, of Boston,..even suggests mineralogical names, such as ‘cementite’, ‘perlite’, ‘ferrite’, for the various associations of carbon and iron. 1900Engineering Mag. XIX. 752/1 This substance, which has received the name of pearlite, is an intimate mixture of thin lamellæ of ferrite and yet thinner lamellæ of a chemical combination of iron and carbon, Fe3 C, which bears the name of cementite. Low-carbon irons and steels are composed of a conglomeration of ferrite and pearlite, but when the carbon reaches about 0·8 per cent. the ferrite granules disappear, and only the pearlite remains. 1966C. R. Tottle Sci. Engin. Materials x. 228 A two-phase alloy will tend to corrode more readily because an electrochemical cell will be set up between the different areas. Mild steel, containing ferrite (pure iron) and pearlite (a eutectoid, itself two-phase), shows this. 1977Sci. Amer. Oct. 127/1 The presence of pearlite in an iron artifact is a clear indication that the artifact has been carburized.
Hence pearˈlitic a.
1904Proc. Inst. Mech. Engin. Nov. 1149 ‘Sorbitic’ steels..are produced by a much more rapid cooling than is necessary to produce the ‘pearlitic’ steels. 1947Nature 11 Jan. 50/1 Ordinary cast iron has a mixed ferritic-pearlitic matrix, and the engineering irons are usually fully pearlitic. 1962B.S.I. News June 12/2 Draft proposals considered by the committee related to chemical composition, mechanical properties and methods of test for blackheart, whiteheart and pearlitic malleable iron. |