SOVIET WRITERS DISCUSS PROTECTIVE ARMOR OF MODERN TANKS

• Document Type: CREST
• Collection: General CIA Records
• Document Number (FOIA) /ESDN (CREST): CIA-RDP80-00809A000700030523-6
• Release Decision: RIPPUB
• Original Classification: S
• Document Page Count: 5
• Document Creation Date: December 22, 2016
• Document Release Date: August 4, 2011
• Sequence Number: 523
• Publication Date: December 21, 1951
• Content Type: REPORT

Sanitized Copy Approved for Release 2011/08/04: CIA-RDP80-00809A000700030523-6
SECRET
atCuRiTY INFORMMION
HOW
PUBLISk D Monthly periodical
'.>7iERE
PUBLISHED Moscow
DATE
PUBLISHED May 19117
DATY' OF
IJ. .CATION 19147
SOVIET WRITCH DIyCJSS
PROTEC O MO ANKS
SnCr-Lol A. Antonov
Engr-Lt Col Ye. MaCidovich
Tank armor consists of steel plates and steel canting- which are riv-
eted or welded to'ether to fern the arr?orod bod., and turret of the tank.
Special steel containing 0,25-0.115 percent carbon is used for the armor
Of i .;demo; t. -,ks. cart:on in the steel, the harder it. is, but
ineroasing the carbon content also :-,ake the steel more brittle. Brittle
steel is not suitable for armor, a-dch should be hard and at the same time
ductile. The cunhinati~+n of these qualities is obtained by conolez heat
treatment of the sital and addition of nickel, chrome, and molybdenum.
Some of the elements added inc.eane the strength of steel (chrome, silicon,
nsnganero), some increase the ciuetility (nickel, nnn;-anese), and some make
it easier to enchinc and heat-treat tho steel (nickel, chrome).
To combine a high def7ro of eiirface hardness with ductility, the armor
is sometimes cesehardoceri. In the carehardeinr process, a thin layer of
the armor's surface is -aturntei u.th carbon while the rest of the armor
contains covvaratively little carbon. Ar.ior of thi:: kind withstands armor-
piercing; bullets : rd axes not eslit .'mar struck by shell frag.nents. Case-
hardenin;r is crpccidll;; ir:r,orrvnt .:hen t.-ink armor up to !.5-20 millimeters
thick iv use.i for -irot(,ction a:-di r.t LuileV and Snell frar.aents. Promo the
armor of rnodorn trunk- is orirarik, Beni: re I for protection against shells
rather tans bullet:, ,r.:i mince it. it 7()) :millimeters or more thick, homogene-
ous, noncacchnrdonrJ steel Is use:f for tints pur,cse.
Interaction of Projectile and Ar.,or
The ordinar- amor-d ercin, !.hell shatters armor by its kinetic energy,
;roach it oyoreesc i tim fe'nruln:
?i equals ;l'2
2
- 1 -
SECRET
Sanitized Copy Approved for Release 2011/08/04: CIA-RDP80-00809A000700030523-6
 Sanitized Copy Approved for Release 2011/08/04: CIA-RDP80-00809A000700030523-6
SECkti
where M equals the suer, of the -,rojuctile, which equals itr :reillit t: divided
by' the acceleration due to rra
19 equals G equll.s G kilograms x necond2
981
V is the speed of the projectile at the norient it strikes t.a armor.
If the projectile strikes the armor perpendicularly, all of its kinetic
onerrv goes toward knowckin out a "plug", that in, shattering the armor.
The inertia of the armor make., it resist bcndint'. The hi, her the sneed of
the projectile, the less tire there is for the armor to bend, and the greater
proportion of the kinotie cner o' the projectile ,nor toward k pocking out
a plug.
The projectile rarel^ strikes the armor perpendicularly, but rather at
an angle to the pcraendicular. If t e un .le is ll, the force acting on
the projectile from the armor (r-act'on of the, armor), toL,ether with the inertia
of the projectile (aaolled at the center of cavity), tend to turn the projectile,
reducing the angle and incrnasin, the oroJnctilc' capacity for piercing; the
armor. Thin I-- called shifting of the arojectile. if the angle is large, the
forces tend to turn the projectile in the other direction (increasin. the angle),
causing it to ricochet. 'thus, the etreni-th of the armor will depend on the
angle at which the projectile meets it: the vreater the angle, the leas chance
that the armor will be shattered. To increase this ant le, the armor is mounted
obliquely iherever aosnable. gblique ariaor lenlt',ens the aistance the projec-
tile must penetrate and is thus c.ual in protective value to a thicker plate of
vertical anaor. ibis -akes It. ans-ii le to wake oblinee s,:.retr thinner and
thug re fume the wiei, ht of the ,r.-,or.
mall angles of deviation from the oern ndicular (up to 10 degrees) have
little effect on the piercing utility of he arojectile. For this reason,
the angle of inclinatior.,i' the armor ir; usually no less than 20 degrees.
At an ar..le of ';0 de, roes the oroject.i to ricochets.
The kinetic energy of the projectile dopenis on the ve.locit_ with
which is striker the armor. ':hn ;rector ttt^ lirtance from the i,un to the
point of l.mact, the ,-rertrr the .lose ir. velocity of the projectile in
flight., and the rraallor the i.'rict velocity. Tt :rust be noted that the
irsroact vetocit;: is scuared in .+:, for.aria no tact reducing it by two times
decrea!acr: the kinetic crr:rr': ae.: h:rnce t.hc :eiorcin, ability of the projec-
tile t`y four tines.
The eroiactivo thickness of ar.or in t:r.t thic;ness idth which the
inner (rear) c urface of the = _or riot break, that is, .toes rot show
cleavage or fins, !: -. a veto,;ty of 75,0-'000 meters per second,
the protective thickness of the c.- of e