878
action of the acid produces a different effect in thethe two cases.
Steel for ship plates and angles should not containmuch above T per cent, carbon. If such metal isalso free (to about the same extent) from siliconand phosphorus, it not only does not harden, eventhough it may contain nearly a half per cent, ofmanganese, but is rendered tougher by repeatedlyheating and plunging into cold water. It can alsobe welded with facility, although it requires morecare than iron. Such metal will possess a tensilestrength of from 25 to 28 tons per square inch, andwill elongate from 25 to 30 per cent, in a length of8 inches before rupture. For boilers the steel maycontain up to '25 per cent, carbon without becomingtoo hard. The extra carbon adds considerablestrength and stiffness to the material, while it tendsto prevent oxidation. It does not weld quite aseasy as the softer kind, but still may be weldedperfectly. It hardens very slightly, and in the softstate possesses a tensile strain from 28 to 34 tonsto the inch, with an elongation of 20 to 25 per cent.For rail steel the carbon may range from '25 to '5per cent., and the tensile strain will run up to about45 tons to the inch, and the elongation over the 8inches decrease to about 10 per cent. Tool andcutlery steel may contain from J to 1-J per cent,carbon, and the tensile strength will increase up toabout 70 tons to the inch, the elongation decreasingfrom 5 to 1 per cent. By particular modes oftempering, such hard steel, when free from otherelements, may be strengthened until, in the stateof wire, it will stand a strain of over 100 tons tothe square inch.
Carbon steel becomes hardened by cold rolling or
hammering. The appearance of the fracture is agood guide to the quantity of carbon present in asteel free from other elements. With from one totwo tenths per cent, the fracture will be silky andalmost fibrous, with "5 per cent, it becomes coarselygranular, while with 1 per cent, the grain becomesvery fine and silvery.
Carbon tends to prevent red shortness; but as thefusing point is rapidly lowered by an increase in thepercentage of carbon, it is important to workthe more highly carburized materials at a heat notabove blood red, while the softer varieties may boworked at a white heat.
Silicon produces both red shortness and coldshortness in steel. In the absence of carbon theseeffects are not very marked, but when very smallproportions of carbon are present the action ofsilicon is very decided. Thus, when the carbon is'under T per cent., silicon may exist up to -6 per cent.,or more, without rendering the steel particularlybrittle. Such steel could be heated and quenched inwater, and afterwards bent double without cracking,while the tensile strength was not greatly increased.It also worked well at a bright red heat. On theother hand, when the carbon rises to "4 or "5 per cent.,even - 2 per cent, silicon produces decided red short-ness and cold shortness, and if the silicon reachesone-half per cent, these qualities are developed to adangerous extent. Where steel is not to be worked,however, as in castings, the presence of silicon isvery valuable, as silicon steel runs solid and setsfree from honeycomb, while after annealing itpossesses considerable strength. In the followingtable, No. XIII., there is a case of a steel containing2-44 per cent, silicon and ’40 per cent, carbon:—
Very good Steel forRoll Turning.Crucible Manufac-ture.
. Silicon Steel.
! Very fine grain.Tensile strain, 48tons. Elongation,
3 per cent. |
Ordinary Steel madeby th e direct processat West Cumberland! Iron and Steel Co.’s| Works. Rolledwell, and was very
1 suitable for rails.
Crucible Steel forPunches—stood well.
Punch Steel,
| too hard to temper,cracked in hardening
Crucible Tool Steel ,remarkable for itsturning properties.
Steel Rail, workedremarkably well—W.Cumberland Ironand Steel Co.—notthe least red-short.
Steel Plate which
1 would not take acoating of tin—West CumberlandIron and Steel Co.
BessemerSteel Punchmade at W.C.I. & S.Co. ’s W orks—worked
3 weeks without re-setting, & punched1500 rails, or 6000holes. Only oncetempered.
| Red-short Steel,
owing to excess ofsulphur.
Terre Noir Steel.Made in Siemensfurnace from oldiron rails and scrap.
Iron,.
97*893
96*140
98-558
98-696
98-737
98-000
98-656
98-784
98-586
99-180
98*820
Carbon,.
2-000
•400
•370
•940
•820
1-850
•480
under - 100
•350
•340
•230
Silicon,.
•093
2*440
■011
•130
•112
•144
•018
•833
•335
trace.
•102
Sulphur,.
•014
•060
•030
•008
■006
•029
•022
•043
•038
•160
•063
Phosphorus, ..
trace.
*026
•057
•026
•095
trace.
•061
•075
•073
•060
•130
Manganese,...
trace.
*880
•974
•200
•230
•230
•763
•216
■691
•360
•662
Total,....
100-000
lOOOOO
100000
100-000
100-000
100-253
100-000
99-951
100-073
100-000
100-007
analysis of steel of vakious qualities.— Continued.
Terre Noir Cast
1 Steel. Very solid,
j without blow holes.
Creu 2 ot Gun Steel.
Crewe Steel Plate.
Red-short Steel.Red-short fromexcess of sulphur.
; Red-short Steel.Red-short fromoverblowing.
i
Steel for ,
1
Plate Steel for Boilers and Ships.
Crucible Manufac-ture.
Steel for Castings, ‘made withSilicon Pig. j
Steel for Castings—very sound & quite ;free from blowholes, i& exceedingly bard— \Turned Steel whichMushet's Steel ,
1 Test—stood 34
tons tensile strainj per square inch.
Elongated *20 per| cent.
Test—27 tonstensile strain.Elongated 27 percent.
Test—28 tonstensile strain.Elongated 25 percent. 1
Test—31 tonstensile strain. IElongated 20 per [cent.
Iron,.
98-241
99-003
99-411
99-207
99 376
99-679
98-779
—
_
98-379
97*900
97-250
Carbon,.
•450
•405
•260
•250
•200
_
•400
none.
•090
•140
1-280
•420
•500
Silicon,.
■384
•010
•052
—
•056
—-
•102
■018
•005
•028
*112
•521
•251
Sulphur,.
•063
•010
•024
•133
•Oil
•040
•019
—
_
•050
•085
Phosphorus, ..
•085
•025
•029
•05
•044
•022
•081
•031
*056
*026
■028
•058
•043
Manganese,...
•777
■180
■244
•360
•313
•259
•616
•273
•259
•259
•201
1-051
1-380
Total,....
100 000
99-633
100 000
100-000 jioo-ooo
100-000
100-000
—
—
—
100-000
100-000
99-509