|

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
Steel3 _2 A0 ]: X; R0 r; B2 C
Class Notes and lecture material" ?3 ^+ D6 r3 e$ y
For
7 s, Q6 i! a/ w" z' d! B* }4 ?MSE 651.01--
+ x! }+ }8 r3 A% y/ MPhysical Metallurgy of Steel
/ L1 T4 |: D2 L3 u8 @1 S2 a- c& pNotes compiled by: Glyn Meyrick, Professor Emeritus, I7 ^5 h# c6 o% m, f9 O
Notes revised by: Robert H. Wagoner, Distinguished
! H' T3 a7 J2 o9 z7 ?9 AProfessor of Engineering) l! W* a0 a/ q4 w8 C8 J
Web installation by: Wei Gan, Graduate Research Associate1 N2 F. f3 |3 Y
Last revision date: 1/8/01
5 \, |+ Y3 D/ b4 L11/ p8 A1 _3 d- U* e( }( h
STEEL; r4 @7 B' ]: e$ t( b
Foreword6 T' m# [5 O9 e N J
This document is intended to augment formal lectures on the general topic of the physical
# F$ H: D) v) M" emetallurgy of steels, presented within the MSE Department during the Fall Quarter, 1998. It is
$ b1 C4 j- C( X7 ~ Ebased on a variety of texts and published articles and also on personal experience. Specific$ i+ @. o( @9 e, i* D3 G
references to sources are made within the document. However, the material is often in the form of
% u; j* V7 u2 s l$ I& Bknowledge that has been accumulated by the work of many people and is "well-known" by experts
0 i* _# y) q( \! J! P, @( z( Jin the field. A detailed acknowledgment of the work of each contributor to the field is not attempted
) \2 J2 l8 f: Z. {because that would be an awesome task. This document is not intended for publication and is. a! a5 D0 r- Y% S+ P2 i5 p
restricted for use in MSE 651.01.9 T% [2 I+ o. u* Z7 A$ d9 i* u
Texts: Steels; Microstructures and Properties by R.W.K. Honeycombe (Edward Arnold)
2 x# D$ U9 X" G( @9 k4 {2 nPrinciples of the Heat Treatment of Steel by G. Krauss (ASM)0 w( Q0 p' N* H( r: y2 m8 I
The Physical Metallurgy of Steel by W.C. Leslie (McGraw Hill)* x5 c" M m! d% h; _2 F/ f
The ASM Metal Handbooks.
( P& c* _# f2 N, i8 V% c& QHandbook of Stainless Steels, Peckner and Bernstein (eds.) McGraw Hill 1977
, v x# Y6 c4 m7 [: `Tool Steels Roberts and Cary, Edition 4, ASM, 1980- m' ^6 j( \* P& c/ b/ {, U9 _
Ferrous Physical Metallurgy A. K. Sinha, Butterworths 1989.
1 ]3 u' _; U. G5 t- jIntroduction
0 f2 w n- v, B% b: x3 |; t4 U/ d5 \1 gSteel is a family of materials that is derived from ores that are rich in iron, abundant in the
$ o, k' @3 Y: O7 B9 NEarth’s crust and which are easily reduced by hot carbon to yield iron. Steels are very versatile; they
8 v; a9 P' Y2 C: ycan be formed into desired shapes by plastic deformation produced by processes such as rolling
5 I9 C* z o9 g- ]' B* l+ h$ O aand forging; they can be treated to give them a wide range of mechanical properties which enable8 j3 v6 a1 G+ b! C
them to be used for an enormous number of applications. Indeed, steel is ubiquitous in applications* h' d8 \1 ^. n+ D
that directly affect the quality of our lives. Steel and cement constitute about 90% of the structural8 b9 Y I) D2 M: l" P
materials that are manufactured2 s4 Z' {, W( R2 ]" a/ F' g+ S
( Westwood, Met and Mat Trans, Vol. 27 A, June 1996, 1413).
5 x7 K7 W1 f7 p/ ~8 A. r/ L5 Z0 }What, then, is steel?( y9 J9 v" o8 A ^7 P( l @
A precise and concise definition of steel is not an easy thing to present because of the very: q% b7 u* M$ o
large variety of alloys that bear the name. All of them, however, contain iron. We might reasonably, {% b3 q2 ~' K# m/ H7 ]0 l9 C& Q
begin by describing a steel as an alloy which contains iron as the major component. This is only a3 G3 _( J" Z; N' W
beginning because there are alloys in which iron is the major constituent, that are not called steels;/ R# N: B" \1 ]: _2 N
for example, cast irons and some superalloys. The major difference between a cast iron and a steel8 U2 A" r: ^; a; m# K
is that their carbon contents lie in two different ranges. These ranges are determined by the- q% N# C }$ D8 [* \
maximum amount of carbon that can be dissolved into solid iron. This is approximately 2% by
) R" n L8 e) Q( A; q6 Vweight (in FCC iron at 1146 °C). Steels are alloys that contain less than 2% carbon. Cast irons- S# n- a1 w! b" @- ~' {# l
contain more than 2 % carbon. Many steels contain specified minimum amounts of carbon. This
+ b8 q' S, `6 \4 z- x' Tdoes not mean that all steels must contain substantial quantities of carbon; in some steels the8 w u. i0 A/ U2 n- m
carbon content is deliberately made very small and, also, the amount actually in solution is reduced+ @0 g2 |# f# N' A/ i3 U; D
further by the addition of alloying elements that have a strong tendency to combine with the carbon" Z+ \5 l0 m/ e1 \9 o# K
to form carbides.
- s( M+ _! b$ j( {Steels can be divided into two main groups; plain carbon steels and alloy steels. The latter$ H! b) s: s; Z$ S v
can then be subdivided into many groups according to chemistry ( e.g. standard low alloy steels),
1 w) L, m/ n- g9 B- S* D" s- \4 Aapplications (e.g. tool steels ) or particular properties (e.g. stainless steels) etc. Let us begin with8 l5 ]( X. r C
22/ L6 A: @6 n" y }
plain carbon steels; this group is the simplest to understand and it comprises steels that are used in
9 h, p5 i+ K+ Y$ dthe greatest tonnage |
|