Are you sure of the chemical analysis?
1000 ppm Cr = 0.1% Cr and
857  ppm Ni = 0.0857% Ni would not make up a stainless.
It is not clear why your customers should find the composition of your products.

http://www.welding-advisers.com/

I didn't do the analysis, so I have to go by what the numbers say.  

I dug a little further and found out some more info.

My product is food grade powdered sugar.  Our customer runs the product across magnets as it unloads from a rail car.  They found 'highly magnetic' pieces on the magnet after processing a certain car that had my product in it.  The samples were sent to my home office and analyzed with the above results.  

Thinking about it a little more, I realize this is not stainless (especially with the low chromium and nickel numbers).  I asked for carbon content, but the sample was consumed in the first test and carbon was not analyzed.  

I'm sorry if this is in the wrong forum.  I didn't see a steel group.  Mods can move as necessary.

Sounds like rusty carbon steel detritus has made its way into your sugar.

Michael McGuire
http://stainlesssteelforengineers.blogspot.com/

Or weld slag.

Nah, it wasn't welding slag.

Current thinking is a bearing came apart somewhere in the process and the magnets and metal detector didn't catch it.