From what I understand, Xten-50 is the generic grade of Corten which many companies are using due to the lead time/cost of Corten. So, unfortunately Corten is not always an option. Although not exact, they have very similar properties but I have been unable to find a corrosion comparison which would give a good indication of longevity due to corrosion compared to Corten. Is there such a thing published anywhere?
I believe that "Corten", "XTen" and "TriTen" are all registered to United States Steel Corp, so XTen is not what you would call generic. If you can get XTen with .5 copper content, the corrosion resistance in your application should mirror that of Corten.
EffHeat, A few years ago I wanted a few tons of Corten in UK and was told "only available if you want 1000 tons" If it is the same in USA maybe the answer to your question is of accademic interest only since you need a big number of fan blades for this amount of Steel.
Regards CM
Depending on your thicknesses and stenght levels you required, try searching for material under ASTM specs instead of trade names. Try ASTM A588, ASTM A606 type 2 or 4, or ASTM A709 Gr. 50W or HPS 70W. All are considered "Weathering" grades of steel. ASTM A606 gives a forumula to calculate the corrosion index for weathing steel, and could probably be used as a rough approximation. A lot of weathing steel in the US goes into bridge structures. If you search for data on weathing performance of bridges, you might be able to come up with some data.
In Europe the CORTEN type weathering steels are covered by EN10155. As GRoberts says - you may have more luck tracking it down using generic national specifications.
Regards
I am unsure of the quantity of material they use but I know they do use Corten and often use Xten-50 interchangeably. Claiming that these materials are interchangeable is where the issue lies as a corrosion comparison is not something that they have been able to produce. From reading, it is my understanding that these materials are interchangeable from a material strength standpoint, which I have documentation to support this, but they are not from a corrosion standpoint. Although I am reluctant to find any supporting documentation.
I will repeat what the others repeat--you need to talk about material specifications, not trade names. If the terms are being used generically, then it means absolutely nothing to quibble about corrosion data for one trade name vs. another. In the end, these products are manufactured to a published standard, and they are under no obligation, no matter what past data may show, to produce to any level higher than that standard. So either the published standard (for whatever brand you buy) meets your requirements, or it doesn't.
Right now the only COR-TEN[®] products I see listed on the U.S. Steel website are roofing materials. I can't even find "Xten", but maybe I'm just searching badly.