|

楼主 |
发表于 2011-3-6 17:40:02
|
显示全部楼层
来自: 中国湖北武汉
Steel5 M* ]# P. P) K, \9 o; [) Z
Class Notes and lecture material
% U. a& F8 K' R7 c/ b3 o8 C/ HFor! R5 N- W1 `7 l, _) B' Y5 ~& M: G
MSE 651.01--& u! X1 }5 }/ T' |+ c+ z! i
Physical Metallurgy of Steel6 a3 l$ E F4 `, ?) T$ j
Notes compiled by: Glyn Meyrick, Professor Emeritus
1 j f- ]! x+ k8 N) {( qNotes revised by: Robert H. Wagoner, Distinguished
$ z3 i8 O. ?, k3 k# ZProfessor of Engineering. @& [, V% O+ n4 t+ i$ |
Web installation by: Wei Gan, Graduate Research Associate/ r) r: l/ J7 @: a+ |8 O5 J
Last revision date: 1/8/01
9 Z% {7 T: D* N! h& d116 v4 M! `0 a/ e# a, g
STEEL/ r* w% ^! j0 w8 r" w4 N0 p
Foreword
% v; g, z; l, _; j1 i: ?4 sThis document is intended to augment formal lectures on the general topic of the physical
1 ]" I) m. z' J5 v8 mmetallurgy of steels, presented within the MSE Department during the Fall Quarter, 1998. It is
; ?) S6 ?' U) e! s" p% C5 _based on a variety of texts and published articles and also on personal experience. Specific5 l! j. d& |" n# n! N8 g
references to sources are made within the document. However, the material is often in the form of4 ^8 Y/ a6 s- g0 l4 B& G `- ]
knowledge that has been accumulated by the work of many people and is "well-known" by experts
) |+ g; D# w C5 ]# iin the field. A detailed acknowledgment of the work of each contributor to the field is not attempted% A; F) l) X1 s/ U4 `# ?9 v
because that would be an awesome task. This document is not intended for publication and is
4 B7 E/ K: _7 Qrestricted for use in MSE 651.01.% `2 f* s# V4 x$ p
Texts: Steels; Microstructures and Properties by R.W.K. Honeycombe (Edward Arnold)
6 y' T( |3 Q* z( }5 x4 [Principles of the Heat Treatment of Steel by G. Krauss (ASM)
, N: `; e) C8 a5 L% ]$ ^: MThe Physical Metallurgy of Steel by W.C. Leslie (McGraw Hill)# y6 M- \& [* N0 q8 p
The ASM Metal Handbooks.2 X4 L0 c2 Y' @
Handbook of Stainless Steels, Peckner and Bernstein (eds.) McGraw Hill 19775 E# Z" v. h- n2 x8 t: r6 @
Tool Steels Roberts and Cary, Edition 4, ASM, 1980 ]0 K0 o. z, I0 }( E- _ L
Ferrous Physical Metallurgy A. K. Sinha, Butterworths 1989.1 ~9 z5 \' F: u7 y7 k+ x
Introduction/ F! \2 F, B+ b8 b% Z# k) i
Steel is a family of materials that is derived from ores that are rich in iron, abundant in the
: ?; }' ?0 b7 X. |2 G1 Q+ UEarth’s crust and which are easily reduced by hot carbon to yield iron. Steels are very versatile; they
: z& I- _" s+ ]/ \can be formed into desired shapes by plastic deformation produced by processes such as rolling
R' ^: b! V3 }- s7 v9 Q1 Nand forging; they can be treated to give them a wide range of mechanical properties which enable
; @+ E" b7 Y0 ?them to be used for an enormous number of applications. Indeed, steel is ubiquitous in applications+ L, ?4 W j4 Z7 H+ }
that directly affect the quality of our lives. Steel and cement constitute about 90% of the structural; C3 p/ K* }7 W3 I! S# [5 A5 _
materials that are manufactured' l4 e }. C0 P2 A, m0 p' r! d
( Westwood, Met and Mat Trans, Vol. 27 A, June 1996, 1413).1 v; {* k* X3 ~! F; j* Q' C0 C$ B* ]
What, then, is steel?
0 f8 s/ B [+ E% U% i* oA precise and concise definition of steel is not an easy thing to present because of the very2 a! u5 j( r! X
large variety of alloys that bear the name. All of them, however, contain iron. We might reasonably7 Y, c& r$ I$ P. J
begin by describing a steel as an alloy which contains iron as the major component. This is only a& {8 Q( F4 Z: ^
beginning because there are alloys in which iron is the major constituent, that are not called steels;
. ]1 n7 |6 |* Zfor example, cast irons and some superalloys. The major difference between a cast iron and a steel, s8 q( y# ]% r$ R9 S( o
is that their carbon contents lie in two different ranges. These ranges are determined by the
, B- e1 c" Z' ?# r, N) ?# mmaximum amount of carbon that can be dissolved into solid iron. This is approximately 2% by
# U( X1 `5 B! x; T! Q1 C" Zweight (in FCC iron at 1146 °C). Steels are alloys that contain less than 2% carbon. Cast irons; E; n( t' Y2 ~
contain more than 2 % carbon. Many steels contain specified minimum amounts of carbon. This
1 H0 W- ?8 D/ q4 _does not mean that all steels must contain substantial quantities of carbon; in some steels the) d" I6 y+ F1 j1 R
carbon content is deliberately made very small and, also, the amount actually in solution is reduced
z2 }0 l b E/ \further by the addition of alloying elements that have a strong tendency to combine with the carbon
# j% U) f- q% B- F! Dto form carbides.
% F/ b6 l& I& `3 ^3 X- [/ iSteels can be divided into two main groups; plain carbon steels and alloy steels. The latter
* ?5 p$ Q9 y8 K8 e9 w8 Acan then be subdivided into many groups according to chemistry ( e.g. standard low alloy steels),- w/ I/ r! E$ W6 V
applications (e.g. tool steels ) or particular properties (e.g. stainless steels) etc. Let us begin with6 [/ b9 _+ P+ r& z- y
22 u) l. l9 o# O: S9 H7 g/ `
plain carbon steels; this group is the simplest to understand and it comprises steels that are used in
* x4 z' T" g p# tthe greatest tonnage |
|