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Material replacement

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LuizGuimaraes2011

Industrial
Jul 27, 2011
2
BR
Hello!
I want to replace 316LN stainless steel with 316 / 316L double specification.
Can I do it?
 
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The strength of 316LN is higher, and it has slightly better corrosion resistance.
What is the part/product form? What do you do to it (machine/weld/coat/ ...)?


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P.E. Metallurgy, consulting work welcomed
 
If it is a piping / heat-exchanger tube or shell / pressure vessel in an oil and gas installation (existing or under construction), you cannot do it.
Unless you agree to generate tonnes of paper-work, which I always feel is more tedious than sticking to the original specification.


DHURJATI SEN
Kolkata, India

 
This is a downgrade of material. Whether the downgrade is acceptable or not is up to your analysis and it appears that you are presently clueless as to why the 316LN was originally selected for the service.
 
Thank you to everyone for the interest in helping me!

The 316LN was first selected due to good toughness, but our purchase team is finding difficulties to buy it. And we are trying to substitute this alloy to the dual specification 316/316L. We thought that taking advantage of the best properties of these two we would achieve the 316LN.

Another question: What is the percentage of nitrogen in the dual specification?
 
It is unspecified so it is uncontrolled. It could be as high as the "N" grade, or it could be 0.0001%.
It depends on who makes it.
All of these austenitic grades have good toughness, if they were annealed properly (no residual delta ferrite), but their toughness is limited by the very low yield strength.

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P.E. Metallurgy, consulting work welcomed
 
Ed,
My copy of SA-240 shows a maximum N content of 0.10 for 316 or 316L. 316LN shows a range of
0.10 - 0.16.
 
You are right Don, plate and sheet (and maybe bar) have a 0.10 max N for non-N grades.
However for tubing there is no max for non-N grades.
The product for matters, check the specs.

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P.E. Metallurgy, consulting work welcomed
 
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