Armour Metallurgy Properities

Warship design and construction, terminology, navigation, hydrodynamics, stability, armor schemes, damage control, etc.
Aviamata
Junior Member
Posts: 2
Joined: Thu Jul 15, 2021 2:45 pm

Armour Metallurgy Properities

Post by Aviamata » Thu Jul 15, 2021 2:59 pm

Hi , i have some question about Metallurgy Properities but can't find any good information about it .

Does anybody have any infos about WW1 and WW2 battleship and cruiser armour (Especially American , British , German and Japanese) properities like Tensile Strength , Yield Strength , Hardness , Density and Composition ? . I know there are many in formation from Nathan Okun but i heard that his figure are wrong and also the figure he is giving is so low ( the figure of WW1 battleship steel is so much lower than the steel use in WW1 tanks ), maybe he is using the wrong units but i just come here to ask everyone . So if you have any source or document about it , please share i'm very grateful of that , Thanks !

Thorsten Wahl
Senior Member
Posts: 785
Joined: Mon Apr 27, 2009 4:17 pm

Re: Armour Metallurgy Properities

Post by Thorsten Wahl » Sun Jul 18, 2021 11:16 am

German naval plates
20210718_125808.jpg
20210718_125808.jpg (99.73 KiB) Viewed 253 times
German Dehnung%(DIN) is not Elongation% used in US (imperial) terminology.
(Lenght thickness ratios of specimen are different).
And non naval plates( even very thick ones) may have the same composition but different physical properties. They were ballistically optimised for lower caliber attack. And may perform worser against large caliber attack.
Meine Herren, es kann ein siebenjähriger, es kann ein dreißigjähriger Krieg werden – und wehe dem, der zuerst die Lunte in das Pulverfaß schleudert!

Aviamata
Junior Member
Posts: 2
Joined: Thu Jul 15, 2021 2:45 pm

Re: Armour Metallurgy Properities

Post by Aviamata » Tue Jul 20, 2021 2:33 pm

Thanks , It's this table apply to all German warship from ww1 to ww2 ? or maybe there was other steel classes?

Thorsten Wahl
Senior Member
Posts: 785
Joined: Mon Apr 27, 2009 4:17 pm

Re: Armour Metallurgy Properities

Post by Thorsten Wahl » Sat Jul 24, 2021 5:27 pm

Only WW2
Meine Herren, es kann ein siebenjähriger, es kann ein dreißigjähriger Krieg werden – und wehe dem, der zuerst die Lunte in das Pulverfaß schleudert!

User avatar
Dave Saxton
Supporter
Posts: 3113
Joined: Sat Nov 27, 2004 9:02 pm
Location: Rocky Mountains USA

Re: Armour Metallurgy Properities

Post by Dave Saxton » Wed Aug 04, 2021 1:52 am

The numbers are not hard and fast for physical properties. It depends on the hardness level and the heat treatments. For example, the typical tensile strength of armor grade steels hardened to 250 brinel hardness, is about 75 kg/mm2. If the hardness is 300 BH then the TS increases to about 90 kg/mm2. However, you will see a reduction in the elongation and reduction of area specification as hardness increases. It becomes more brittle as it gets stronger and harder. If the hardness is reduced to 200 BH then the tensile strength drops to around 60 kg/mm2, but the elongation spec will improve.

I have the properties that the Tirpitz deck armor plates tested by the Norwegians.
The panzer deck was 80 kg/mm2 at about 250 BH.
The oberdeck was 75kg/mm2 at 235 BH
It was clearly a superior material. The composition was:

C-0.29%
Si-0.32%
CR-2.41%
Ni-1.81%
Mn-0.26%
Mo-0.49%
Cu-0.11%

I don't have the exact composition for the Japanese homogeneous armor on my present computer, but I recall it was essentially the same stuff as the British NCA.
Entering a night sea battle is an awesome business.The enveloping darkness, hiding the enemy's.. seems a living thing, malignant and oppressive.Swishing water at the bow and stern mark an inexorable advance toward an unknown destiny.

Post Reply