I have dried and collected as much wood chips as possible and have been burning them in my coal furnace.
They burn great. I can cold start the coal furnace by stuff about 30 lb of wood chips and light a fire on top of and it takes about 5 hours to burn away.

I finally sharpened the blade. It was smashing through the green wood more than cutting.
The blade appears to be fairly high alloy. More alloy than tool steel but not quiet high speed steel.
A sharp blade is much nicer.

This is what the chipper blade is made of, from the DR website:
"our knives are made of high-carbon/high-chromium forged alloy tool steel"

Yeah most tool steels don't have a lot of chromium.
Add a little tungsten and it would be high speed steel