Krupp KC-Panzerstahl
Kohlenstoffanteil: 0,34 %
Nickelanteil: 3,78 %
Mangananteil: 0,31 %
Chromanteil: 2,06%
Spezifisches Gewicht: 7,82 g/cm³
http://forumarchiv.balsi.de/waffen_gera ... index.html
Weiterhin Daten von http://gva.freeweb.hu/index.html...Und das beim Auftreffen von Geschützgeschossen auf eine
Panzerplatte innen Stahlstück rausbrechen, (Stahl ist viel zu spöde, nichte elastisch genug) kommt nur bei´sehr minderwertigem Panzerstahl, unde speziell auch be gegossenen Panzertürmen (s. Russ.) vor, das ist aber eher
ein Thema für die alliierten, speziell für die russichen
Panzerungen, die z.Z. so große Lufteinschlüssen und verunreinigungen aufwiesen, das schon diese Luftein-schlüssen für Beschußspuren gehalten wurden ...
Gerade der deutsche Panzerstahl galt bei allen Experten,
auch und gerade bei den der allierten, als Extrem hochwertig, das ehr zäh und wiederstandfähig, und es gibt da auch sogar so eine Berechnung von Heereswaffen-versuchsamt, nach zahlreichen Beschußversuchen,
vonach 100mm deutscher Panzerstahl ( "Kruppstahl" )
in etwa die gleichen Wiederstandwerte aufwiesen hätte wie 135mm US-Stahl, oder 155mm russicher Panzerstahl.
Da gibt es auch ein nettes Bild von einem Pershing, der
auf der Wannen- und Turmfront eine Zusatzpanzerung aus
Stahlpaltten montiert hat. Das Pikante dadran ist, das
die US-Besatzung die Platten aus einen zerschosseen
deutschen Panther I geschnitten hatte ...
... denn dieser Panther I hatte wohl im Gefecht mit 5 Pershing, 3 Pershing ausgeschaltet, wobei der Panther I
auch mehrere Volltreffer an Wannen- und Turmfront bekommen
hatte, ohne jedoch auszufallen. Erst durch einen Wannen-Seitendurchschuß mit nachfolgenden Explusion der Bordmunition konnte einer der der beiden verbliebenen Pershing diesen Panther I aussschalten !
Gut das es zum Kriegsende natürlich zu Engpässen bei der
Rohstoffbeschaffung gekommen ist, ist klar, und das hier
und da auch der legendäre Kruppstahl dann nicht mehr so
perfekt war ist auch kein Thema.
Aber als die Ami´s 1945 die Krupp-Werke in Essen besetzten, war eines ihre Hauptintressen das sie die Herstellungs-verfahren für den deutschen Panzerstahl in die Hand zu bekommen würden !!
Es zeigt sich, daß sogar amerikanische und britische Panzer bis spät in den Krieg Probleme mit schlechter Stahlqualität hatten, während es auf deutscher Seite dann 1944 anfing. Auch spricht die Bearbeitungs und Fertigungstechnik für eine überlegenheit der deutschen Panzerungstechnologie.Cast Armour
Cast armour is made by pouring molten metal into moulds which are shaped as the required vehicle component. After removing from the moulds the rough spots, risers and gate marks are ground off and the component is heat treated. Heat treating consists of heating, quenching (rapid cooling in water) and tempering as described for RHA. Cast armor is never worked or squeezed down into thinner form as rolled armor is, therefore it has an inferior grain structure and lower ballistic resistance.
Cast armor is always homogeneous and was never face hardened (apart from a few experiments). The difference in hardness between the outer surface and inner surface found on some cast armour is more a result of poor heat treatment or insufficient alloy content than any intentional effect intended to increase ballistic resistance. Homogeneous armour works best when it is the same hardness throughout, as changes in hardness form stress concentration boundaries which significantly degrade ballistic resistance.
Cast armour resists less well than rolled armour of the same hardness and thickness. USA tests of production quality armour in 1942 and 1943 showed this clearly, in which 51mm (2 inch) thick test pieces of cast armour showed a 15% to 20% inferiority compared to 51mm (2 inch) rolled plates when hit by 75mm projectiles. The tests also demonstrated that rolled armour can be raised to higher hardness levels than cast armour without losing ductility, and therefore ballistic resistance.
Rolled Homogenous Armour
Rolled homogenous armour (RHA) is essentially cast metal which has been further worked and shaped, aligning the grain structure of the metal and thus increasing its ballistic strength. It is made by first pouring molten metal into moulds and allowing it to cool and solidify into ingots. These big barrel shaped pieces which come out of the moulds are pounded with giant hammers to form billets which are then rolled at the rolling mill to become slabs. The rolling mill uses tonnes of pressure on a wide roller above and another below the red hot steel slab. The slab is rolled many times, in at least two perpendicular directions (cross-rolling), until the desired thickness is achieved.
The steel must then be hardened. It is re-heated to the transformation temperature (above 800°C) and plunged in water. The rapid cooling works molecular changes so that the steel becomes very hard, providing the alloy content is correct. It is then reheated to just below the transformation temperature and cooled again. This last step is called tempering and reduces the hardness while greatly increasing the ductility. The steel is now called rolled and homogeneous, that is, it has been shaped by rolling and the molecular structure is generally uniform throughout the cross section.
Face Hardened Armour
Face hardening (FH) is a method used to increase the armour hardness of the surface of armour plate. The rear side of the armour plate remains at its original hardness. Face hardening is carried out by taking a slab of RHA and heat treating it again, but on one side only. The heat treating is time consuming and results in a warped plate which must then be flattened in large presses. The Germans were able to handle plates up to and including 50mm thickness (with production oversizes up to 55mm), and tried 80mm FH on the early Panther glacis. Later on the Germans found a way to use a heavy electrical current flow through the steel to induction-harden one face. Both methods were used until the end of the war.
The purpose of the hardened face is to shatter an incoming projectile’s head before it can penetrate. The Germans found it resisted Soviet uncapped AP and APBC projectiles quite well, when the armour plate thickness was around the same size or not too badly overmatched by the projectile (such as Pz.Kpfw.IV 50mm front armour vs. Soviet 45mm or even 76mm AP or APBC). Britain and the USA tested projectiles against FH armour as a matter of course until about 1943, but rarely used it on production vehicles because of its relatively poor resistance to German APCBC in comparison to RHA. The Germans were faced with APC and APCBC from the Western allies only, not the Soviets, so their decision to use FH armour weakened their tanks against Western guns but strengthened them against Soviet guns.
Flaws in Armour Plate
To complicate things even further, some armour plates were flawed which significantly affected their ballistic resistance. The only way to determine the presence or absence of flaws is to sample the steel in question and run metallurgical tests. By deduction, premature ballistic failure as recorded in field tests indicate the presence of flaws, such as the several tests of captured Panthers which had poor quality glacis plates (which includes the report of tests of Soviet 100mm and 122mm guns against a captured Panther at the Kubinka Proving Ground found in the library at the Russian Military Zone).
It was determined reliably that a large proportion of USA armour, both cast and rolled, produced prior to November 1943 was flawed to such an extent that it resisted about 5% to 50% less than it should have (mean resistance around 85% of 1944-45 armour plate). Also British armour of greater than 57mm to 63mm was flawed until about 1944.
The BHN of steel is not directly related to flaws. Some Soviet T-34 BHN 450 armour was relatively flaw free, while other plates of the same thickness in the same tank were quite flawed, as shown by tests conducted by Watertown Arsenal in the USA.
For the technically minded: flaws are things like stringers, laminations, inclusions, and transformation by-products which are in dirty or improperly heat treated steel. Flaws also include crystalline microstructure, as opposed to the ductile microstructure of correctly made, sufficiently alloyed steel.
Unten aufgeführt die typisch verwendeten Panzerbleche der Hauptkriegsgegner mit Brinell Härte Faktor. Dazu zu sagen ist auch, daß ein zu Harter Stahl leichter reißen kann und auch gegenüber Aufschlagskappen (APC) empfindlicher ist.