overlay in MR 0103

[smart143]

I have previously qualified weld overlay as below.
Base material was A240 316 & ER 316 rod as filler metal.

the hardness survey done on weld metal(overlay) shows reading varing from 242 HV10 to 249 HV10.

Out of 20 reading on weld, only one reading shows value as 249 Hv10.

Does that mean this procedure is not complying to MR 0103 as hardness is exceeding 248 HV10 (22 HRC)
The hardness reading on base material post overaly are between 230-240 HV10 which is fine.

A quick reply is highly appreciable.

 

[SJones]

Does ASTM E140 give you a hardness conversion for HV to HRC for austenitic stainless steel?

Steve Jones
Materials & Corrosion Engineer

http://www.linkedin.com/pub/8/83b/b04

 

[metengr]

Why are you even using hardness testing on an austenitic weld overlay??

 

[smart143]

metenger,

These wetted parts require NACE MR0103 compliance so hardness test is done on weld overlay.

 

[metengr]

I agree hardness testing is required for wrought, austenitic stainless steel base material to ensure no remnant cold work for this type of service.
Let’s think about this, you overlay the wrought stainless steel base metal with an austenitic stainless steel overlay that is not air hardenable, why would hardness testing be applicable for the weld overlay (base metal is justified as I explained above)? If the component is cold worked after the weld overlay, this defeats the purpose of hardness testing for the WPS.

 

[smart143]

metenger,

Refer attached file which shows the actual construction & provide your feedback.

 

[SJones]

You still haven't answered the question: how are you converting from HRC to HV?

Steve Jones
Materials & Corrosion Engineer

http://www.linkedin.com/pub/8/83b/b04

 

[stanweld]

Smart143,
You appear to be plugging a tube with a most unconventional approach. That is by stuffing the tube with bare filler metal and melting the ends to form the plug. Is this the case? If so, this is not a weld overlay.

 

[smart143]

stanweld,

That is the product requirement & we are using additional filler wire to melt the end face of stuffed filler wire so its similar to overlay. Now customer wants MR0103 compliance for the same.
Do you have different idea to suggest the weld procedure to this unusual product?

Sjones,
Apology for not answering your question at 1st instant but conversion was done by test lab & we did not asked them-how they convert it.

 

[stanweld]

Why not use a tapered 316L plug and weld it to the existing 316 overlay?
Your current weld is not a corrosion resistant overlay; it is a pressure containing weld.

 

[smart143]

no, its not pressure containig weld but certainly placed in pressure parts. Its actually used as senser in flow meter so definitely working pressure & temp will affect it.
We can not alter the mfg process as it may not provide the signal. currently its working fine with set process.
So what type of procedure qualification is required for such type of weld?
At the moment qualification per corrosion resistant weld is mutually agreed between customer & us.

 

[stanweld]

So you are manufacturing a pressure sensing instrument for which the welding procedure need not be qualified per ASME IX. Your contract and agreements thereto govern.

 

[smart143]

stanweld,
Thanks for the feed back but the original question remains unanswered.

 

[SJones]

It remains unanswered because the acceptance criteria are in HRC, but the measurements have been made in HV10. See MR0103, sub-subclause 1.5.7

Steve Jones
Materials & Corrosion Engineer

http://www.linkedin.com/pub/8/83b/b04