All metals smelted after 1945 unavoidably contain traces of radioactive nuclides that were created and spread around by atmospheric nuclear weapon tests carried in the 1940s and 1950s. Consequently they are faintly radioactive and unsuitable for use with many sensitive scientific experiments and measuring instruments.
So the raw steel from shipwrecks that occurred before 1945 has special value because they are uncontaminated and can be cut (without smelting) and used that way.
So the raw steel from shipwrecks that occurred before 1945 has special value because they are uncontaminated and can be cut (without smelting) and used that way.