Material grade (Stainless steel) distinguishing problem! 6

[Engineerator]

We are having corrosion problem with some bolts that are supposed to be stainless steel(A2), when we sent a sample to a chemical analyses agent , we have got a chemical composition report differ from BS EN ISO for grade A2(Austenitic). Now, when some elements(C, Cr,Ni, etc..) abundance are differ between ISO standard and the actual chemical composition, what we would do? Are there some elements we only have to look at or all elements abundance have to be as per standards? In order to take decision whether this material or that are comply to standards or not.

Thank you..

 

[Metalguy]

Can you post the requirements and the actual numbers?

"You see, wire telegraph is like a very long cat. You pull his tail in New York and his head is meowing in Los Angeles. Do you understand this? Radio operates the same way: You send signals here, they receive them there. The only difference is there is no cat." A. Einstein

 

[Engineerator]

actual chemical composition file is attached.

 

[arunmrao]

They comply against the A2 grade as per BS EN ISO 3506. The carbon is quite low in your actual sample 0.022%against a maximum permissible of 0.1%. Similarly are other elements too,within the specified range. In the case of Copper a maximum of 4% is speified and minimum not mentioned,hence your actual values of around 2% falls within the range.

Hope this helps.

 

[Metalguy]

What kind of corrosion problem do you have? Actual pitting or is it just rust-colored spots?

If the former, you probably have a chloride-ion problem. If the latter, you probably have bolts which have non-stainless steel imbedded in them from processing.

In the latter case, passivating should eliminate the problem.

"You see, wire telegraph is like a very long cat. You pull his tail in New York and his head is meowing in Los Angeles. Do you understand this? Radio operates the same way: You send signals here, they receive them there. The only difference is there is no cat." A. Einstein

 

[TVP]

As arunmrao mentioned, the composition for the bolts meets the requirements for A2 ISO 3506-1. You should investigate the type of corrosion as Metalguy pointed out.

 

[Engineerator]

Thank you all, my problem was how to read the chemical composition.