I have found some mentions in two books below - it is about ironworking technology in ancient China (page 184 in first one and page 295 in the second one). Maybe you will find it useful or interesting from historical point of view.

https://books.google.cz/books/about/The_Archaeometallurgy_of_the_Asian_Old_W.html?id=WyVmAAAAMAAJ&redir_esc=y

https://books.google.cz/books?id=mxZsguBzwZMC&dq=Iron+and+Steel+in+Ancient+China&hl=cs&source=gbs_navlinks_s

Dear Prof. Vahdati Khaki,

I have found some papers concerning the solid state decarburization of cast iron. The following links may be useful:

1. http://www.maneyonline.com/doi/abs/10.1179/1743281212Y.0000000032?mobileUi=0&journalCode=irs

2. https://www.jstage.jst.go.jp/article/tetsutohagane/98/5/98_5_151/_article

Best Regards

Dear Prof. Vahdati.

I wish you are fine. I have some experiences regard the decarburization happens during the solid (pack) carburizing of low carbon steels. I think it may be useful for you and you can download the corresponding papers from my page.

If you need more information about that, we can contribute together through the email.

Best wishes.