Considering its looks, it is a piece of some casting. Judging from the surface grain, it is not a rough sand casting, so perhaps more of an investment type of casting, suggesting some greater structural requirement than a rougher sand casting in my mind. Material analysis would also help determine its usage and elemental composition.
That seems to have a small-ish diameter from part the guessed curvature in that picture, and with the possible severed/lost numbers relating to the mould, design and production/foundry company, I think it is not rom one of that outer/outside cast part of the engine casing or outer rim of a structural web, but that is just my opinion of gut reaction.
If it isn't part of a bearing hub/web or outer casing or perhaps a of a cast accessory component, then it might be from the cast central internal supporting structure that the combustion flame cans were mounted around and the compressor/turbine connection shaft oil and cooling air passed through - or maybe part of the inlet ducting/outer wall of the inlet duct perhaps.
Certainly it has a scuffing mark upon it suggesting something passed across it - perhaps a compressor blade or other shrapnel upon impact destruction or combat damage, it doesn't appear to be burned in a blackened way - soil erosion/corrosion might have cleaned that off, but is likely to be doubtful; carbon is chemically easier to bond too than other elements - if I managed to remember some school chemistry, so it if from the internal central web, that was surrounded by secondary cooler airflow - this is still assuming/hoping it is from that central part.
Could you provide more photos please, of its side(s) and back too if possible for others as well to theorise, and to try and guestimate its curvature size and hence narrow down its possible position.
Might the location where its from yield further parts/pieces, and is within/under an archaeology framework, or is that the hope to getting archaeologist involved?