Okay, I just realised that Steel requires Thermodynamics, and not the other way, which is strange, since historicly the knowledge of Steel is earlier than Thermodynamics.
I think it would worth flipping the two and than move Ironworks.
The Steel tech is really shorthand for the Bessemer process (patented 1856), allowing steel to be used on a wide scale for construction and engineering purposes. Yes, steel is known long before that, but only on a small scale, and I am not about to create separate techs for "crucible steel" or "mass-produced steel" or "Bessemer process" and just do one simple Steel tech.