May 18, 2017
I work for a privately held company. But ALL of our customers are publicly traded and therefore I must answer 100's of individual inquiries for the same information each year.
Tantalum is added to a very few alloys of stainless steel. Steel is melted and remelted. If the chemistry at the steel mill says they have enough tantalum (less than .8% by weight Tantalum and Columbium combined, so who knows) then they pour the melt. If they are low, they add an alloy high in columbium and tantalum, or they add a compound containing tantalum. (or columbium, or both) When the melt meets specification requirements, they pour.
Then they sell the steel to a mill. Then that mill sells it to a tube mill. Then the tube mill sells the tubes to a distributor. Then I buy tubes from the distributor. I do not know where that 1/8 of an ounce per pound of 347 alloy stainless steel comes from. I do not even know if I sell a customer 347 alloy stainless in any given year.