If you start comparing Titanium alloys to Steel then the comparison gets even harder. Titanium alloys are in general stronger than steel as well as much lighter and more corrosion resistant.
4340 steel isn't exotic. It's one of the most commonly used grades of steel out there, and it's much cheaper than titanium. There are steels out there with significant stronger yield strengths too. Meanwhile the highest yield strength of any Ti alloy is <1300MPa.
Titanium is still a really great material in certain applications. But it's not magic. You have to use it intelligently in the right application to get a benefit from it.
When you go to both maximum cold (cryo fuel), and you go to maximum (reentry heat) then steel is amazing.
Aluminum would turn to butter on reentry, it would require a massive amount of heat shielding. Titanium alloys would have same issue.
Titanium alloy also become to brittle in deep cryo.
So steel beats everything in this demanding application. Its amazing.
[0] I mean real wrought iron -- the almost 100% elemental stuff -- like the Eiffel tower is made of. This is practically unobtainable today. The "wrought iron" you commonly see for sale nowadays is always mild steel. And "cast iron" is actually very high carbon steel, not iron. Cast iron so high in carbon that it's brittle and cannot be forged or easily welded.
[1] It's a myth that mild steel cannot be hardened. With a proper wetting agent added to the quench, you can harden it significantly.
> "general" or common steel and "common"/"general" titanium
Why would you compare 'trash-quality' steel vs exotic and expensive material like Titanium?
That does not make any sence.
>4340 steel is an ultra-high strength steel
https://en.wikipedia.org/wiki/4340_steel
The alloy composition calls for 0.2-0.3% molybdenum and expects accuracy to within a few per mille for ten elements. Moly is considered so important that there are entire towns in the United States established to mine it to secure the military supply chain.
The others mine molybdenum as a byproduct of copper. I guess you could say the Bagdad mine has a company town, but it wasn't made to secure the military supply chain 140 year ago.
