884
STEEL. —Mechanical Properties.
The above tests of English material, from theWest Cumberland Iron and Steel Company, weremade by Kirkaldy for the Board of Trade (seeTable XVI. '* A summary of the results of experi-ments to ascertain the elastic and ultimate tensilestrength of twelve steel plates, annealed, receiveddirect from Messrs. West Cumberland Iron and SteelCompany, Limited.” Nominal thickness, quarter,half, and three-quarter inch.) All test pieces weretaken from plates of ordinary manufacture, selectedby the chief engineer of the Board of Trade. Thesteel was made by the Bessemer process, a mixtureof ferro-manganese and spiegeleisen being used. Theingots were hammered into slabs about 6 inchesthick, reheated and rolled into plates at one heat.The annealing was done in a Siemens furnace.
The analyses of these plates gave the followingresults:—
Cast A B C W
Iron,. 99-274 .. 99-099 .. 99 550 .. 99-036
Carbon,. -140 . -200 . . -100 .. -240
Silicon,. trace. .. trace. .. trace. .. -159
Sulphur,. -030 .. -046 .. -057 .. -040
Phosphorus,. -030 .. *015 .. -027 .. -021
Manganese,. *590 .. -640 .. -489 .. -504
On the whole, it will be seen that this material isof very high class, as the mean tensile strain of allthe samples cut lengthways is 30 tons per squareinch, and the elongation 25 per cent.; while one ofthe samples, with a strength of 28-1 tons, elongated32-4 per cent. This is a greater elongation than wasreached by any of the samples of the chain cable irontested by the United States committee of experts,and reported on by Holley, the best result of thewhole series giving only 29 - 9 per cent, elongation,with a tensile strength of 24-2 tons, while the averageis very far below this standard. It will be notedalso that the material is nearly of the same strengthand elasticity when tested crossway, in which respectit again far exceeds iron. It appears that the thinnerplates give a higher tensile strain and lower modulusof elasticity than the thicker ones. This is whatmight be expected, although the annealing to a greatextent removes the hardness produced by rolling.
In 1870 a committee of the Institute of CivilEngineers presented an elaborate and valuablereport upon “ The Mechanical and other Propertiesof Steel,” from experiments made at the WoolwichDockyard. The following table, No. XVII., is ex-tracted to show the connection between chemicalcomposition and mechanical properties. The analyseswere performed by E. Richards, of the BarrowSteel Works, and Dr. (Idling. It is to be regrettedthat there are serious discrepancies between theanalytical results of these two chemists, which havenot been cleared up, as they render it diffcult todeduce conclusions from the observations.
The enormous quantities of steel now used forrailway bars renders any observation upon thematerial employed of great consequence. Numerousobservations have been made upon the effect ofpunching upon this kind of steel, and all investiga-tions corroborate the statement first made by Bram-well, that punching or notching deteriorates such
H
H
02
Eel
Ratio offractured tooriginal sec-tional area.
Total
extension ofbar in partsof a foot.
Yielding
point.
Compression
Yielding
point.
Tension.
Ultimatetensile stressper squareinch.
ocoooit'W , co oo .•^oooor-*Ho^oioioco -no th ocojot^COO)OO)01O> 1 lO lO I 40 OO >0 05 05
— COT* GOC5 x*
(fiiOM'fLS'O CO in C5 CO CO lO COC5 00 05 CO »H —I .COCO I 05 10 0COHN(OOh 5)M COrt [ GO IT3 oO OO- rH x}( 1 OlH 1 MridlOfM
00 c-
t— x*C5 00
to tx»
t>ooor~ooooot>»ocooo
1—IIOOO-'HOOIOOOWOCOOO
cbiocbdocfi- ! ctf^Ocb<M?Hcbioi>*'ct4
(MCDNHHlMCIClHClOIrtHeiCl
O O O O co o*n o © m co o
o o co m oo >o 00 toO CD cb O
os oo to to co co o
I HtOCDCDTh OO to
I cb cb cbco co co co co
I I I M I I I I I I I I I I I
r-i i-H -«* UO
CO m T* <N «■*OO OO 00 OO OO
05 ©
m inoo oo
t- C- CO <N Oi m in in m m| oo co co oo oo
t-» t> t> t>»
x* o.
r> to»n co
I I
' C505
o o o o o
t*» C'» co t> ooCO 00 to 00 00
o oto
I V T 1
1 05 <0505 05
o o o o ©
-H <N CO toI (NDDMHH* rri
311 i i if i i Ml i i
i i
o oo oo o
I I i 1.8 I I I I 8 I I I
ooooo oo ooooo
(N^tOHlN I <M 04 I CO 04 04 r-l CO
ooooo loo looooo
I! i i i i| i i i i|!i
cuoooo aio oooocJ
OHCKNIM / OH I O
goooo 1 ~ 1 --
-w I ~*T1 C.N xjl W
go I o o o o g
INI;
I I
I I
ooooo
CO CO CO to
o o oooooco m © co 05
TH <N | CO X* CO XJ1 iH
© CO . IOi -H I I
I I § I I I I 3 I I I
O O 4) O o»O H 3 N o
ooooo
m one ^
o o
I 05 xM . . _
I <o X* I co co co co in
ooooo
-rh 04 rH in CN1 j
OS’S.3 a
I [
s_ O
H a
U h
05 U
EE >»o •**
cl d
■S-e
U eg
48 CO*
1 0=3 I'
1 « g
cS M■4 03
03 (3
a» o
bi’-ja p<
>>.2Eh Ah
‘E mft
11 :
g • n
r-T ! ’
<r> .52 ® ao •
-3 T3 !
h « a to ;
03
§ 8 : -‘5 2 -I" 3 "“3|l
2 £ 2 _r
5 dq ^
"j 0 « -a to -
J33 -jg "
a u » *
03 03 <0
a
j P2 'o-h'*
C3
*H
s gg 1» S c «
2 oo
o
Boon
ts o •a 2 *w p4 :
gSda
u g.fa.iS"3 CO u g