This was a project for my sister's house in Berkeley.
She wanted a bare iron awning for the back patio so it would rust into a natural patina.
I was unable to source the parts in California so I had the pieces fabricated in Oregon from Corten steel, and shipped.
Corten is designed to rust to a certain depth and then stop. Pretty much every rusted sculpture you have ever seen is made from Corten steel.
It took a week to install, and has been there ever since.
As I warned her beforehand, there is some rust staining on the ground wherever the rain runs off the awning, but that has not been a problem.