EN 10025-6: S690QL hardness

[wontweldcantweld]

Hello all,

I'm looking for some guidance regarding a welding qualification: I am looking to qualify EN 10025-6:2019 S690QL. The customer specification lists some quite demanding mechanical testing, though the one I'm worried about is the NACE hardness acceptance requirements, plus the customers additional cruciform hardness.

Looking through EN 10025-6 however I can't see any limit on hardness for S690. Can anyone advise where this may be stated - I know it will be on the material certification though it hasn't been ordered yet, and I'm aware there may be a caveat for materials as-received that are already above the hardness requirements.



Thanks

 

[RolMec]

Hi,
this steel is dedicated to high yield high Charpy applications in welded structures, so hardness is not the standardized feature. What I'd do is to check for a suitable ultimate strength to hardness translation eg from EN ISO 18265 and then to prescribe a corresponding value to the steel supplier or else. Also, it helps to talk to the / a supplier .... you know the drill
regards

 

[kingnero]

What is cruciform hardness? Have been doing PQR's for almost 20 yrs now, never heard that.
Do you mean regular hardness tests (ISO 9015-1) on a cruciform test specimen? Shouldn't be a problem, values will be lower than a regular T joint due to higher heat. I'd prefer a micro + grain size test on S690QL.

ISO 15614-1 mentions max. 450 HV non heat treated. Shouldn't be a problem, it's more likely you overcook the material and deteriorate the properties.