Welding 316/316L Material - Does ER316 Filler Exist? 1

[beh188]

If you weld dual rated 316/316L material do you need filler that is dual rated also, or can you specify strait ER316L filler? I have seen ER316/ER316L filler, but I am under the impression that it is really ER316L composition. Is there such a thing as ER316 filler? I am wondering if there is a strength difference between ER316/ER316L versus strait ER316L.

 

[XL83NL]

You'll always want to use the L-grade, look it up in your filler manufacturer handbook.
This also applies to e.g. 304 -> weld it with 304L.
If you dont have one, request one. They provide good practice and insight.

 

[metengr]

If you weld dual certified TP 316 stainless, I would recommend using L grade filler metal because this would better match the dual grade.

If you are welding 316 stainless, there is no harm in using L grade. Where you need to use higher carbon content base and filler material is for elevated temperature service.

 

[stanweld]

To add to metengr re high temperature service, use ER316H.

 

[moltenmetal]

For high temperature service (beyond 1000 F), both the parent AND weld metal need to be high carbon H grade.

Pardon my ignorance, but don't you need dual grade filler to weld dual grade pipe? It doesn't seem logical that you could substitute filler meeting only the L grade, without this material also meeting the strength of the straight grade as well? Or does the extra ferrite typically found in the weld deposit (by design due to the filler metal composition) give the L grade material the same or greater strength than the straight grade spec for the parent material already?

 

[blacksmith37]

As noted "H" is required for ASME high temp service ( I thought
"high temp" was below 1000F).
I think of it as more of a money issue: if C <0.035 - mill gets premium for "L", if C > 0.04 - mill gets premium for "H". Looking at actual creep data (40 yr ago) there was no apparent difference.

 

[Duwe6]

The dual-grade for the basemetal simply means that;

1st -- the carbon content is low enough to meet the "L" designation. Low carbon improves weldability.

2nd -- the mechanical strength is high enough to meet the 'plain' designation.

316L is allowed to have a lower tensile strength than 316. When the tensile strength of a batch of "L" base metal is high enough to meet the minimum for 'plain', that batch may be dual-certified. Filler metal designated as "L" has always been able to meet the strength required for 'plain', thus there has never been a need to specify filler wire as "L" or 'plain'.

 

[metengr]

Just a clarification, the L grade is for low carbon content to reduce sensitization as a result of welding, exclusive of weldability.

Weldability for austenitic stainless steels has more to do with minimum ferrite content in the weld deposit to avoid hot cracking.

 

[beh188]

I came across this helpful welding document available from Lincoln Electric.

http://assets.lincolnelectric.com/a...xConsumables-Murex-MurexTIG316316L/c64000.pdf

It details various considerations for welding stainless steels. Based on the Lincoln website they manufacture ER316 and ER316L filler, but it appears that they produce one product which meets both these specifications. That is, the carbon content of the filler is below the requirement for the L grade so it meets both specifications.