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Raf · 8th June 2023, 03:39 PM

Is it old?
I didn't realise until reading an article recently that all steel manufactured after 1945 is radioactive. Not a cause for concern as the amount of radiation is minute but it does mean that post war steel is different to pre war steel . This is because processing steel uses large quantise of air or oxygen therefor some background radiation from atomic bomb testing is absorbed by the steel . Other sources of radiation can be radioactive materials used in furnace linings or contaminated steel inadvertently incorporated in recycling. This has led to a dubious market for pre war steel often savaged from wartime wrecks and Roman lead , both of which are in demand for some highly specialised applications that require materials entirely free from radioactive contamination.

Since the banning of atmospheric nuclear tests levels of background radiation have been falling and steel currently being produced can be considered virtually radiation free. Nevertheless any object that has been manufactured using steel produced in the last seventy years should show low levels of radiation which would not be present in something that purports to be genuinely old. So unless I have got it entirely wrong this would seem to be an entirely objective non destructive test that could be used to identify some post war forgeries. In the same way that TL testing is used to authenticate ancient ceramics. Anyone want to comment ?

8th June 2023, 03:39 PM	#1
Raf Member Join Date: Nov 2013 Posts: 238	Old steel Is it old? I didn't realise until reading an article recently that all steel manufactured after 1945 is radioactive. Not a cause for concern as the amount of radiation is minute but it does mean that post war steel is different to pre war steel . This is because processing steel uses large quantise of air or oxygen therefor some background radiation from atomic bomb testing is absorbed by the steel . Other sources of radiation can be radioactive materials used in furnace linings or contaminated steel inadvertently incorporated in recycling. This has led to a dubious market for pre war steel often savaged from wartime wrecks and Roman lead , both of which are in demand for some highly specialised applications that require materials entirely free from radioactive contamination. Since the banning of atmospheric nuclear tests levels of background radiation have been falling and steel currently being produced can be considered virtually radiation free. Nevertheless any object that has been manufactured using steel produced in the last seventy years should show low levels of radiation which would not be present in something that purports to be genuinely old. So unless I have got it entirely wrong this would seem to be an entirely objective non destructive test that could be used to identify some post war forgeries. In the same way that TL testing is used to authenticate ancient ceramics. Anyone want to comment ?