S460G2+M VERSUS P460NL1 1

[sovog]

I have material P460NL1 to be welded (8mm fillet) and have an existing weld procedure for S460G2+M.

I have checked the Max chemical values and Min yield strengths and as far as I can see they are more or less similar and within range of each others Max & Min requirements other than the P & S abbreviations.

As the P = Pressure and S = Structural can the weld procedure using S materials be utilised to weld P material?

 

[metengr]

sovog;
What is the application for welding and code of construction for the above? I have exposure to some foreign boiler/pressure vessel construction standards and most have very specific requirements for prohibiting substitution of structural quality steels with pressure vessel grade steels.

 

[sovog]

metenger
Thanks for your response.

The welding will be carried out with GTAW / GSFCAW process. The client has not clarified fabrication and welding code at this point but we are proposing ASME IX code in our bid.
This project is a structural fabrication which within it utilises some pipe fittings


We are not making a substitution of material grades from the required grade specified on drawing which is P460NL1 but are unsure if an existing structural procedure utilising S460G2+M grade material would be suitable for welding the P460NL1 materials.

 

[metengr]

sovog;
I reviewed the chemical composition requirements for the P460NL1 in one of my reference books, and it is not similar or equivalent to S460G2+M. The P460NL1 material for pressure service is more characteristic of a fine grained, high strength low alloy steel when you review the "other" elements category besides C, Mn, P and S contents. In addition, you really need to review the material specification for this material regarding mechanical property requirements. Based on what I have seen so far, I would qualify a separate welding procedure specification using P460NL1 material.

 

[sovog]

metengr

Thanks very much for your advice it was most helpful in confirming the need to qualify WPQR for particular material grade.