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来自: 中国湖北武汉
Steel
* [- U( k- G5 I& `7 P; a- Z$ cClass Notes and lecture material" R7 |7 @0 X5 G1 o# Q
For
4 ^: o3 }: u" JMSE 651.01--9 q# P0 M. u# Y2 \
Physical Metallurgy of Steel) \' p3 x7 r4 ~ s& n$ M1 b+ G
Notes compiled by: Glyn Meyrick, Professor Emeritus
@* I$ `" u9 cNotes revised by: Robert H. Wagoner, Distinguished
8 [ `( C' l1 w( x; s+ j8 s( F$ `Professor of Engineering+ n4 @5 o. y' u' N
Web installation by: Wei Gan, Graduate Research Associate
$ z( V4 j3 {( SLast revision date: 1/8/01
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STEEL6 @1 [ J4 j0 _0 d
Foreword
0 G& ]/ a6 p! O/ A0 O: G& VThis document is intended to augment formal lectures on the general topic of the physical
- M, ]' z4 A/ A2 T. r2 c0 \metallurgy of steels, presented within the MSE Department during the Fall Quarter, 1998. It is
. N7 K3 S/ O' Y z, o* mbased on a variety of texts and published articles and also on personal experience. Specific( r; z+ p$ a1 l, _6 Y
references to sources are made within the document. However, the material is often in the form of
! @! d0 `& N. E9 x1 R1 t# y% J. ]knowledge that has been accumulated by the work of many people and is "well-known" by experts& j3 Q7 K3 E# w
in the field. A detailed acknowledgment of the work of each contributor to the field is not attempted
' e- g/ W! u. C6 J2 b mbecause that would be an awesome task. This document is not intended for publication and is
2 G) S$ }# [( O- ^' q3 m% hrestricted for use in MSE 651.01.
! ^$ [: k/ W7 [' j2 M3 o% o$ r2 BTexts: Steels; Microstructures and Properties by R.W.K. Honeycombe (Edward Arnold)- B1 O+ d9 h: }4 H, [/ H& Z
Principles of the Heat Treatment of Steel by G. Krauss (ASM)* o# |5 R4 R! X9 \0 i
The Physical Metallurgy of Steel by W.C. Leslie (McGraw Hill)
/ I& V$ G! @4 a7 G2 \The ASM Metal Handbooks.9 u, `1 f* H4 _; t; _
Handbook of Stainless Steels, Peckner and Bernstein (eds.) McGraw Hill 1977 s0 G" @1 i" a7 a# \
Tool Steels Roberts and Cary, Edition 4, ASM, 19804 k4 ~' [3 R, j z
Ferrous Physical Metallurgy A. K. Sinha, Butterworths 1989.* U2 {& h& H! V4 @/ T" F# D
Introduction
- z3 }2 f" A/ kSteel is a family of materials that is derived from ores that are rich in iron, abundant in the
7 P4 n/ J, Q, A3 K" qEarth’s crust and which are easily reduced by hot carbon to yield iron. Steels are very versatile; they/ B2 h, m' \% P. D0 O
can be formed into desired shapes by plastic deformation produced by processes such as rolling ?7 B9 Y: o4 E: M
and forging; they can be treated to give them a wide range of mechanical properties which enable
/ e' \& |& B- @1 ithem to be used for an enormous number of applications. Indeed, steel is ubiquitous in applications* p; j( D# U U- a( A% l
that directly affect the quality of our lives. Steel and cement constitute about 90% of the structural
# F; k4 V( W* y; X; smaterials that are manufactured1 H: G' a1 R) l# p/ Y+ |
( Westwood, Met and Mat Trans, Vol. 27 A, June 1996, 1413).
5 ^' L% |! }- s; Q/ cWhat, then, is steel?
( [, Z% q! ]1 D; k/ h* d/ b5 XA precise and concise definition of steel is not an easy thing to present because of the very& n2 B* ^- s1 m
large variety of alloys that bear the name. All of them, however, contain iron. We might reasonably( r+ J0 V4 x0 c# X1 Z0 S7 I8 Q
begin by describing a steel as an alloy which contains iron as the major component. This is only a; F0 b+ Q. \) T2 y; m4 h
beginning because there are alloys in which iron is the major constituent, that are not called steels;: i7 h# t& r6 I" B
for example, cast irons and some superalloys. The major difference between a cast iron and a steel* x" z( h( \8 d; P1 G' @2 T& |$ }* [0 t
is that their carbon contents lie in two different ranges. These ranges are determined by the
! q# J$ l) ^) N7 bmaximum amount of carbon that can be dissolved into solid iron. This is approximately 2% by+ k8 L* b3 _* B& M4 {
weight (in FCC iron at 1146 °C). Steels are alloys that contain less than 2% carbon. Cast irons
" o6 o u T; b3 C2 Ocontain more than 2 % carbon. Many steels contain specified minimum amounts of carbon. This4 l7 M( r7 ]/ T5 e; X) S1 T
does not mean that all steels must contain substantial quantities of carbon; in some steels the
% u: p, Q/ W+ g$ D8 Scarbon content is deliberately made very small and, also, the amount actually in solution is reduced7 m: M8 N8 W8 e+ h1 W9 {
further by the addition of alloying elements that have a strong tendency to combine with the carbon7 G6 [1 s( }; n2 g% B
to form carbides., {1 X7 m+ O# c/ e
Steels can be divided into two main groups; plain carbon steels and alloy steels. The latter% Y7 W% c8 I, _
can then be subdivided into many groups according to chemistry ( e.g. standard low alloy steels),
* X. k5 k$ j; R7 F Vapplications (e.g. tool steels ) or particular properties (e.g. stainless steels) etc. Let us begin with+ d& s/ E& F0 K3 n
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plain carbon steels; this group is the simplest to understand and it comprises steels that are used in
! H7 [: `0 Z. ^; Hthe greatest tonnage |
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