I have it Steve, but thanks.

re: "burnt" steel. "Burnt" steel has specific metallurgic criteria.

Back in 1895 it was diagnosed visually. "Tempering Of Steel Tools" in the lower right
https://books.google.com/books?id=NkdCAQAAMAAJ&pg=PA20&lpg

Google "The Overheating and Burning of Steel" by Ko Tsun. It is on the internet as a PDF but I couldn't link it.

http://www.engineeringenotes.com/metallu...etallurgy/25931
Overheating is due to the solution of MnS in austenite at high temperatures, and its subsequent precipitation during cooling as fine particles (0.5 – 1.0 µm) of MnS at austenite grain boundaries.
In ‘burning’, formation of a film of sulphur-rich liquid takes place at the austenite grain boundaries. The damage is total and permanent, as the steels than lose their ductility and disintegrate during deformation.

https://sites.google.com/a/damascusknowledge.com/www/home