Dear All

I want to know whats the minimum carbon content allowed in SA-516 60 as per ASME II-A.
Whats my understanding is that the code allows lower carbon content than the "max" mentioned in the chemical composition table with a subsequent rise in "Mn". And there is a "max" limit of Mn as well.
So that would be the minimum C content acceptable as per code?????
Which in case of SA-516 60 is 0.18% ??? Am I interpreting correctly ???

Thanks in anticipation!!


Faisal

Code mention about maximum carbon content only and not the minimum carbon content. An increase of 0.06% for Mn is allowed above the maximum specified limit for every 0.01% reduction in carbon content below the maximum specified limit.

In your example, considering 1/2" thickness (Max C= 0.21%), with a reduction of 0.03% (Max C= 0.18%) in carbon content, I can increase Max allowed Mn by 0.18% above the maximum specified limit (0.06% increase for every 0.01% decrease of carbon).

I am however little a bit lost on note C as indicated in chemical requirement for SA 516 60



I am unable to understand the relevance of this note, why cant we write maximum allowed Mn content for 1/2" or less thickness as 0.6 - 1.2% on heat analysis and 0.55 - 1.3% on product analysis in the table 1 itself if it is allowed in Note C.
Another question coming to mind is increase of Mn is allowed on which limit, limit indicated in table 1 or limit indicated in note 'C'?
Clause for allowing higher Mn with reduction of Carbon content was not there in the spec till 2004 ed and introduced in 2007 edition. To me looks like something missed out while introducing the clause. Not aware if any interpretation or addemdum is available for the same.