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Marseille and other pilots were not lost because of metallurgical issues but due to an oil foaming problem which interrupted the oil flow in the engines which then led to them blowing up.
Thanks. for my sins I spent far too much of my life watching plates being rolled, made into pipes and tested. Fortunately, or unfortunately it was at some of the worlds most advanced plate mills. Even in 1986 when I was at NKK in Fukuyama (now JFE) they were using advanced controlled rolling and accelerated cooling techniques so an X65 plate with hardness of 220VPH and Charpy of 500J was normal. I was interested in the report on tank armour in so far as how much would be done differently today, there would be a transition curve for Charpys and much more hardness testing with Vickers. It occurred to me from the report that the Germans were not only short of alloying elements but also of fuel and also of tanks, heat treatment uses huge amounts of energy how ever you do it. They may have made a decision to produce more tanks at lower quality. I asked about temperature because while captured tanks falling into UK/US hands were probably from Europe or Africa but photos could be from anywhere and tanks were used on the eastern front at very low temperatures easily into the transition temperature of that type of steel.Hey pbehn,
Although grain size would vary a bit from mid-plate to surface, there was probably not as much variation as you may be thinking. The process used to make homogeneous plate almost always involves the hot rolling method, which is effectively a form of forging. Some armour plate was cross rolled, ie 2 rolling directions at right angles to each other. Assuming good quality control, the alloys used and the hot rolling process tends to generate relatively similar grain size through the entire thickness, providing similar mechanical properties through the entire thickness (hence the name homogeneous).
All of the major combatants had specifications for their versions of face hardened and homogeneous plate. At one point in time I had the armour specification data for all the major combatants (except the Soviets) on my computer, but that computer's motherboard failed about a 9 months ago. I have not yet recovered the data due to the uniquely (ie stupidly) propriety (Apple) software/hardware controlled solid state storage device (that is apparently not a normal SSD and was only in production for about 6 months during the second half of 2009). And I did not constantly back it up as I should have.
For the UK series used on their armoured vehicles, although it is incomplete, I still have this for Rolled Homogeneous and Cast Homogeneous armour Brinell values:
View attachment 590064
The US, Germany, Japan, and Italy had similar ranges, although IIRC the German specifications changed more drastically as the war progressed. There were similar specifications for Face Hardened plate, with the face hardness, depth of hardening, and hardness of the softer backing material all specified in a similar manner to the above chart. In addition, everyone had specifications for full-hardness plate (ie hardened all the way through) for a range of thinner plate. There are also other values used in the specifications such as acceptable grain sizes, grain orientation, ductility, tensile/shear strengths, etc.
Although I am not familiar with the Soviet standards in any detail, my understanding from various technical publications is that they were similar to those of the US/UK/Japan/Germany/Italy.
As far as temperature goes, I assume you mean relative to the ambient air temperature when the damage occurred? If so then no, there would be no significant effect. While extreme cold can effect the mechanical qualities of metals, the phenomenon of steel becoming brittle at low temperature that we usually hear about involves much lower temperatures than what was occurring in Europe during WWII. Although I should note that a one time effect on high quality armour plate (such as impact of an AP projectile or blast of a large HE explosion) will not be aggravated by the cold as much as a constant working of low quality (possibly sub-standard?) plate (such as may occur in the hull of a ship at sea).
Hey pbehn,
...For the UK series used on their armoured vehicles, although it is incomplete, I still have this for Rolled Homogeneous and Cast Homogeneous armour Brinell values:
View attachment 590064
...
In terms of the OP one of the conclusions is interesting "Taking the chemical composition into consideration and the History, two trends were observed: Germany, France, and the USA versus UK. The first three nations followed Alfred Wilm's patent, while the United Kingdom developed its own slightly different versions of duralumin."Interestingly, I came across this study a couple weeks back and forgot to post it on another thread. This should answer your question:
Comparison of Aluminum Alloys from Aircraft of Four Nations Involved in the WWII Conflict Using Multiscale Analyses and Archival Study
You seem to misinterpret your sources. It's well known that the DB 605A had a massive problem with foaming oil leading to many failed, blown or bursting-into-flames engines. As this mostly happened under maximum load the engine max power was restricted until the engine was rebuilt to fix the problem. I can't remember to have read of similar problems with later DB 601 types.Your archive references being ____________ ?
Mine are Milch microfilm of RLM stenographic records in Berlin, Volume 16, Frame 2624... October 6th, 1942.
Available from the Imperial War Museum, London.
You seem to misinterpret your sources.
The problem with the stories/myths around the deaths of many Luftwaffe experten is that they were written (or at least polished) by Goebbels's propagandists. Try finding one example of an official account of an experten's demise where they admit he did something stupid or made a mistake, and you will find it a fruitless endeavour. This problem is exacerbated by the post-War indulgence of Western experts that rushed to pronounce the experten as next to godly, despite them having been soundly thrashed by the Allies.It was a really serious buisiness, and did for Hans-Joachim Marsellie as well as many other top pilots.