Test of resistance of a stainless steel to intergranular corrosion (ISO 3651-2 Met. B)

Presentation for participants

Reference of the ILC


References of test methods

ISO 3651-2 Met. B



Each year

Main characteristics

Pass/Fail (3 different types of stainless steels, showing various resistances to intergranular corrosion). Exposure time 20 h.

Other characteristics

Speed of corrosion (loss of mass in a fixed exposure time)


Caution The number of determinations may be low for the secundary characteristics, what may make inefficient the comparison between laboratories


Format of the test results:

Results of some properties are numerical and some are of Yes/No type.



Determination of the assigned values (“true values” for each characteristic)

By statistical computation of the totality of the results with possible selection on competence criteria (accreditation, validation by a reference body, quantity of tests performed in the year), test to detect possible collusion, merging of results not obtained in reproductibility conditions, suppression of technically unvalid results.

Type of statistical computation

For numerical results, the statistical computation will provide an assigned value with its attached uncertainty, values of standard deviations for repeatability and reproductibility, limits of alerts for bias and repeatability of the participant, indiviual values for uncertainty of results of participants.


For results expressed as Yes/No type, samples are submitted to tests by sets of 2 items, with increasing severity, so that cut-off conditions for failure can be determined. The assessment of the results of participants is achieved by reference to this cut-off.

Number of products submitted to tests


Number of samples per participation


Max number of operators per participation

1 (it is necessary to order as many participations as there are participating test operators)

Product submitted to tests

For this ILC, 3 different stainless steels with 3 different corrosion resistances are provided for testing.

Type of samples


Approximate dimensions of samples

Ø8x150 mm

Specific preparation to be performed by the participant

None (other than possible necessity to polish the test specimens or to adapt their dimensions to the equipment of the participant) (2 test pieces per supplied sample)


Special notice for this ILC

The determination of the speed of corrosion is not described in the reference standard, but it helps to make the proficiency test efficient.


Time schedule:


Opening date of registrations


Registration deadline


Date of shipment of samples


Start of the tests


Deadline for carrying out the tests and providing the results


Date of delivery of reports


Note: After the deadline, registrations are still possible. Contact us at ilc@compalab.org for more information.


Price (€)


Price if online payment (€)


Approximate weight (kg)