Permissible amount of Mo in SS 340L in HNO3 application 1

[mthakur]

We know that 304L is the best choice for nitric acid environment due to oxidation issue involved with Mo, when you buy SS304L from the market, it comes with some percentace ( close to 0.03%) of Mo in the form of impuritiy. The questions I have
1. what is the max permissible Mo that can be accepted for nitric acid application
2. what could be the possible effect of Mo in such a small amount if exposed to nitric acid

 

[EdStainless]

In the high purity 310 that is used for strong nitric acid service they often limit Mo to 0.10%.
I don't have any data on Mo in 304 handy.

= = = = = = = = = = = = = = = = = = = =
Plymouth Tube

 

[enmax]

In my experience, there is little difference in the nitric acid resistance of 304L and 316L (which can have 2.0-3.0% Mo) at low temperatures (say less than 60 deg C). It's only when higher temperatures are encountered that the molybdenum content has a detrimental effect. So don't be concerned if the temperature is low.

http://uk.linkedin.com/pub/terry-roberts/28/a9a/a10

 

[gr2vessels]

I have a suggestion, bit out of line;- why don't you people take advantage on the offer from one of most prestigious corrosion resitance experts in the world, the Outokumpu? They have a free corrosion manual, it should be in every engineers bag, it's very useful. Go to Outokumpu website and register for a free copy, it will be shippeed to your door for free! Alternatively, contact your local rep, they should have spare copies in hand. I just got the revised last edition from Outokuumpu's local rep. He came to my work and hand it over to me personally. I also introduced to him few of my young coleagues, because he is a valuable contact. Any corrosion question is replied (for free) promptly, particularly if you call the rep (they have speedy channels at hand).
Cheers,
hr2vessels

 

[Guest102023]

Shopping for heats of 304L with Mo < 0.10 should not be that difficult.

gr2vessels, I have the same manual, shipped to me from Finland - very useful.