A516 Gr 70 Welding Hardness

[Angsi]

Is there a hardness limitation imposed on vessel production welds? I "think" hardness limitation exists for vessels in sour service as required by MR0175, but is there a similar limitation for sweet hydrocarbon service? I keep hearing 248 HV being mentioned but I am not sure of truth in it or where it originated from.

Thanks again.

 

[SnTMan]

I commonly see 200 - 225 Brinnel called out in customer specs, sorry don't know your conversion. Our shop rarely approaches 200.

Don't know offhand if Sec VIII, Div 1 imposes limits or not.

What are you working to?

 

[weldtek]

Each spec is different. Some NACE specs say 248 HV which is the equivalent to 22HRC or 237 Bn, others say 200Bn. I'm not certain if there is a spec which deals with sweet hydrocarbon service. The only requirement I am aware of in Sec VIII for hardness testing, relates, to that required per the original material specification, if heat treating is performed. See UCS 85(c).

 

[JoeTank]

ASME VIII does not specify a weld hardness limit. That is something that would be addressed by the purchaser's spec.

Steve Braune
Tank Industry Consultants

http://www.tankindustry.com

 

[Angsi]

SnTMan....design code is ASME VIII Div 1. But I think Steve is right, don't think ASME mentions anything about hardness limitation.