hardness problem
hardness problem
(OP)
hi
we qualified pqr for inconel 625 clad material(API 5L X65+
3mm inconel 625).the maximum hardness in HAZ on base metal is 252 HV10. our service is soure according to NACE MR 0175.hardness is acceptable or not?
thanks and regards.
R.Salimi
we qualified pqr for inconel 625 clad material(API 5L X65+
3mm inconel 625).the maximum hardness in HAZ on base metal is 252 HV10. our service is soure according to NACE MR 0175.hardness is acceptable or not?
thanks and regards.
R.Salimi





RE: hardness problem
RE: hardness problem
I think you have to consider the hardness requirements for overlay/clad surface (Inconel 625) and base metal (carbon steel) together.
MR0175 requires the hardness limitation, maximum 35 HRC for Inconel 625 and maximum 22 HRC for carbon steel. For the base metal of your concern, the actual hardness, 252 HV is over than 248HV (max. value). Therefore the stress relieving is required.
Hardness Test and Conversion Table; http://www.gordonengland.co.uk/hardness/...
Thomas
RE: hardness problem
RE: hardness problem
I agree with all of you.hardness is more than 22HRC but
where inconel 625 clad carbon steel is used in NACE service
the hardness requirements of the nace document are not
applicable as the inconel 625 cladding dose not corrode and
hence there is no evolution of atomoic hydrogen.therefore the risk of sour service SCC is elimineted.am I right or not?
RE: hardness problem
RE: hardness problem
The second approach would be to justify the readings you have already obtained. How many readings are above 248 and what is the location of these higher hardness readings? Are they closer to the root or closer to the cap? Some codes and specs give different limits for different locations? Is that true in your case ? If not I'd use an approach to justify the higher hardness if it is closer to the cap using this approach and based on EFC 16 where the root hardness permitted is 248 HV10 maximum but cap hardness permitted is upto 275 HV10. This approach woulde need a careful evaluation and a proper justification.....
Thanks and regards
Sayee Prasad R
Ph: 0097143968906
Mob: 00971507682668
email: sayee_prasad@yahoo.com
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