Hardenability for Coupling 3-1/2" L80 13 Cr. material

[gafoorkti]

Please can somebody tell me about hardenability requirement as per API 5CT for Coupling 3-1/2" L-80 13Cr material.

We have received hardness report after tempering, but hardenabilty hardness values for as quenched condition are not mentioned in MTC. As per my interpretation with code, hardenabilty test to be carried out.(Reference API 5CT, clause 7.10.2)
We have raised discrepancy about this and conveyed to manufactuer.
But manufacturer clarifies that hardeneability requirement is not mandatory.

Regards

 

[blacksmith37]

There was no hardenability requirement as originally written and as stated in the 5ed. 1995 (I admit to being obsolete). The hardenability requirement should only refer to C90 and T95; low alloy steels expected to be used in sour service (where hardenability is important).Maybe the spec has been screwed-up in later revisions.
L80 13Cr has very high hardenability and will absolutely pass the (original) 90% martenstite requirement.

 

[gafoorkti]

Blacksmith thank you for your input.
Kindly note that our coupling falls under PSL-2 & advise me on hardenability requirement for PSL-2 product.

 

[redpicker]

The hardneability requirement in 7.10.2 is mandatory, but it only required for each OD, weight, steel grade (chemistry), and austenitize/quench combination. What this means is the manufacturer only has to have documentation that the particular OD size - wall - steel chemistry - and process parameters was tested and met the as-quenched hardness requirements specified, usually as part of their process qualification.

It is not required that this test be performed (or reported) on a per heat or per lot basis for L-80 13Cr. This is probably what your manufacturer meant when he said it was not mandatory. It is mandatory that they perform the test and meet the requirement. It is not mandatory to report the results with the certification package. In addtion, a qualification test performed 10 years ago (or more) is still valid as long as the steel chemistry spedification is the same and the austenitize/quench parameters are the same.

If pressed, the manufacturer should show you the results of this qualification. Since it is a part of their process control procedure, however, they may tell you that is only available for on-site review, that is, they probably will not send you a copy, you would have to go to their plant to see it (during a quality audit, for example). Incidentally, for 13Cr material, this is a slam-dunk reqruirement.

rp

 

[gafoorkti]

Thanks for your advice.