Embrace the rust
if it is made “less flakey”
and almost like paint?
That is the idea of COR-TEN steel such as grades ASTM 242 and ASTM 588
https://en.wikipedia.org/wiki/Weathering_steelsample quote
Disadvantages
Using weathering steel in construction presents several challenges.
Ensuring that weld-points weather at the same rate as the other materials may require special welding techniques or material.
Weathering steel is not rust-proof in itself: if water is allowed to accumulate on the surface of the steel, it will experience a higher corrosion rate, so provision for drainage must be made.
Weathering steel is sensitive to humid subtropical climates, and in such environments it is possible that the protective patina may not stabilize but instead continue to corrode.
For example, the former Omni Coliseum, built in 1972 in Atlanta, never stopped rusting, and eventually large holes appeared in the structure. This was a major factor in the decision to demolish it just 25 years after construction.
The same thing can happen in environments laden with sea salt. Hawaii's Aloha Stadium, built in 1975, is one example of this.[26] Weathering steel's normal surface weathering can also lead to rust stains on nearby surfaces.
end quote
Note the bit about the arc welding rusting faster than the base steel.
I see more and more electrical power line towers made of cor-ten steel than 20 years ago.
I am more a fan of the South African invention: so called 3Cr12 steel,
much less expensive than original 8Ni-18Cr stainless steel
https://www.atlassteel.com/products/3cr12 
