The Republican journal. [volume] (Belfast, Me.) 1829-current, 1917-04-19

os-sr9 Jackets.
.-, 4-mtrd Varships could live in
...r. .aaIe with modern big gun
.afI,. W BSp and hence the max
srulr plate has become
1ac manufacture of armor
..,. has il. I1ped considerably in re-
-.a~. md in no branch of the
.,s. rlaSlv is there greater oppor-
.,7 fu u-Heering and mechanical
All mul, with metallurgical knowl-
MN Ian fu be operations of forging
,r3MIn- u}vWed by the exact heat
+,sarueat essential to produce the al
no,r conflicting properties necessary
n nNH0 amor,
75. atc must be hard, glass hard,
resist reieuatton by heavy projec-
HES nl.m- ut tremendous veIocities,
20, l.. ul fbrous enough to take
m tlq uma.rtum without cracking or
Hss~.a Mechanically, then, the
1ss nus. 6ave an extremely hard
mrta d fibrous backing. These
4e1mHe were attained in part by
t5aa4 .uound armor. Molten steel
VI. f0mat ~ wrought iron plate
sr- .a jAe slab was then re-
he. and rolled to the re-
mr.r lions. If the operations
zs. .l...U.v carried out the line
yfa-. ..u was scarcely visible
1. 4"dilication of this proc
q. ... lIced to cheaper and
ious the production of
.u yer of hard steel was
g-. oolpd mold, the under
Vi. ing. On the still fluid
thick layer of soft
A. "l By careful manipu-
.a a of the surfaces was
L u IT, and it was impossi-
l ... Tie break in composition
F.. .a . fractured section. This
a. -Hulacture was undoubt-
G . ~. ement on the old COM
....0u
I'll. ra-irg size, velocity and
IA taodern armor piercing
D Hs tc uecessitated the intro
l.. I'VE modern armOr. The
if manufacture essentially
4 cSc hardening to a depth
..r '-u inches the surface OF
mA.eous tough nickel chrome
'H ""i air or self hardening
T aG more complex steelS are
,- '.- 5-llter armor. gun shields
a a,t #uored structures.
ta s'ae /, made in Siemens fur
-e 4"d Urefully cast into ingots
o. Eighty IONS in weight. These in
a - t.ea Stabbed under powerful
3p ",Ses $4,000 tons or roll
e' ' he required dimensions,
e- vu The power of the mills
I- #a4aDrps. During the rolling
Is Ich lasts about an hour.
I'd, rersed and inverted to at
a .rl of working. and scale
'" iHy wood fagots and wa
rr l'ter rolling the plate is
'ga 4"ao he'd.
.' pSj Neration is that of case
aasal- and in this two plates are
" '4'e To tace, separated by a layer
.-' 0a7-urlzing reagent if it be
.- r i Gaseous hydrocarbons be
>-- WIG ,.a'es are slightly separated,
"N free passage for the harden
4 NN by bricks arranged in rows.
1F r'a'es are maintained at redness
"a furnace for three weeks and
IlIFlF7|n after the hardening carbon
" penetrated to the required depth.
1t Plates are thus carburized and so
sae capable of being hardened, but
icy are lot vet actually hard. At this
axe Bill holes are drilled and plugged,
WI any bending or machining neces-
ny IS carried out.
''oH mus point onward the treat
e-S differ Some makers insist on
5S'ihs and quenching in oil or water
remove any coarse structure that
Jay nave been formed during the
us 4Jaeaing while carburizing. The
cal essential operation is that of
and this is usually car
'' 41j w one of two ways. Either
'e .'afe Is uniformly heated to the
-''4IiHs temperature and quenched
series Of water jets playing on the
'''t sV'face with sufficient force to
N' Tie formation Of steam or by
l'N'eNr known as "differential
.'AIS' by which the carburized
'''te Is heated to a temperature
'H which it will harden and the
''ei S'le kept well below, so attaining
s''''i'l fall in temperature from the
2 '' ne lotion. The whole plate is
VII immersed in water, the hotter sur
~, ''"iie being hardened. while the
'a is toughened. Further mechanical
'4''ohs can be carried out only by
lung or cutting with oxyacetylene,
.ue plate has now undergone the
-'li'ent comforting maximum hard
SIS
~ resume, it will be noted that there
~ 'uiee distinct operations in modern
i y OF manufacture-the mechani-
, =, Norklng of the plate to the required
'ls''Sions, the carburization of the
80 ,''e quenching the carburized
n '',e 10 harden it. These operations
s 81 'oF exact manipulation, super
~. 'ou and control, for the skill of the
'n and metallurgist may be put
~, ,'e Severest tests, not of the labora-
n, n W The testing machine, but out in
n, gray mists," when failure of a
" may imperil the safety and CO.