difference between 410 and 410S

[jbesson]

Hello Everybody,

What's the meaning of the "S" of SA240TP410S ?

The only difference is the limitation of carbon contents to 0.08 for the 410S, does it means better weldability ?

 

[metengr]

The ASME SA 240 specification is for plate, strip and sheet and for 410S, the carbon max is reduced as you indicated. Take a look at the mechanical properties, and you will see the tensile strength is lower for this material in comparison to standard 410 ss. The 410S made to this specification is weldable under special precautions versus standard 410S with higher sulfur and carbon content.

 

[metengr]

Slight correction to the last sentence,

The 410S made to this specification is weldable under special precautions versus standard 410S with higher sulfur and carbon content.

The above sentence should end at precautions. The remainder of the sentence was not deleted before I hit the send button.

 

[metengr]

jbesson;
Yes, the 410S ss has better weldability than 410 ss.

 

[jbesson]

metengr,

I'm glad that you confirm my thought, do you know a paragraph of ASME code or ASME specifications explaining the signification of this "S" ?

 

[metengr]

jbesson;
I don't exactly remember where the S designation originated for controlled carbon content (between L grade and conventional). I do know that the 410S stainless steel is commonly used in heat exchanger tubing for the petrochemical industry. Also, the S grade is not described in any of the ASME Code and Standards documents.

 

[unclesyd]

I have ran across one reference to where 410S is called a stabilized grade where one could assume that that "S" could stand for stabilized.

The reference to stabilization was made where small additions of Nb was added to improve welding by preventing hardening when quenched from above critical temperature. I have seen one reference that also calls for small addition of Ti for the same purpose.

 

[EdStainless]

What is the upper S limit on 410S ? I have seen very high S material for improved machinablity that is un-weldable. These are broad spec ranges and you need to be careful.

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

 

[metengr]

By specification 0.030% S, similar to other grades of 4xx. 410S was developed for boiler and pressure vessel applications where carbon was lower than standard 410 ss but not low carbon 410 ss , which would be ferritic. The 410S was very weldable.

 

[GRoberts]

If you are thinking about welding qualifications as well, ASME SA240 type 410 is P6 (martensitic), and 410S is P7 (ferritic)

 

[EdStainless]

I have looked up some notes. In BAR product there are mills making 410S with very low carbon (ferritic) and the max S for improved machinability. I have never seen this in sheet or plate.

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

 

[weldtek]

Also, if you're going to be welding type 410, consideration must be given in selecting a suitable filler. I learned the hard way, one can't assume that a 410 filler off the shelf will be adequate.

 

[EdStainless]

I was just looking at the new edition of ASTM. Now the carbon range for these two grades is split, there is no overlap. The "S" is 0.08% max, and the straight grade is above that. The S will not harden and the straight grade will.

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