About halfway down within this paper on this link http://books.google.com/books?id=KisLAAAAYAAJ&pg=PA523&lpg=PA523&dq=what+is+graphitic+softening+in+cast+iron&source=bl&ots=mz9uWoLi40&sig=wCSTEBytYBn4UGVF60WuqkUxnQg&hl=en&sa=X&ei=HgQ0U9yONuPJsQSHzoKgDw&ved=0CEYQ6AEwAg#v=onepage&q=what%20is%20graphitic%20softening%20in%20cast%20iron&f=false
are some interesting reading suggesting all of the precluding scenarios to the embrittlement of the cast iron cylinder being studied and evidently it did not require burial in soil.
Heat played a big factor more than likely as well as original manufacturing process. Im sure there are quite a few heads floating around that would react in the same manner as my own but more than likely few in comparison to original output.
are some interesting reading suggesting all of the precluding scenarios to the embrittlement of the cast iron cylinder being studied and evidently it did not require burial in soil.
Heat played a big factor more than likely as well as original manufacturing process. Im sure there are quite a few heads floating around that would react in the same manner as my own but more than likely few in comparison to original output.