Chemical analysis on non alloyed steel

Presentation for participants

Reference of the ILC	CA24NS
References of test methods	All methods can be used

Frequency	Each year
Main characteristics	C%, Si%, Mn%, S%, P%, Ni%, Cr%, Mo%, V%, Cu%, Al%, Co%, N%
Other characteristics	All other chemical elements existing in steel
	Caution The number of determinations may be low for the secundary characteristics, what may make inefficient the comparison between laboratories

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.
Number of products submitted to tests	1
Number of samples per participation	3
Max number of operators per participation	10 (For this ILC, the type of test and sample size allow to provide results determined by several different operators and by several different methods)
Product submitted to tests	Non alloyed steel
Type of samples	Discs
Approximate dimensions of samples	Ø40x10 mm
Specific preparation to be performed by the participant	Extraction of a test specimen

Special notice for this ILC	All methods may be used. All chemical elements may be determined by the participating laboratory. However, a statistical computation is performed only if a sufficient quantity of results is received. Note: Chemical analysis on metal products is covered by a large number of international standards, see http://www.iso.org/iso/home/store/catalogue_tc/catalogue_tc_browse.htm?commid=46250&published=on

Time schedule:
Opening date of registrations		30/11/2023
Registration deadline		15/03/2024
Date of shipment of samples		31/05/2024
Start of the tests		03/06/2024
Deadline for carrying out the tests and providing the results		23/08/2024
Date of delivery of reports		07/10/2024
Note: After the deadline, registrations are still possible. Contact us at ilc@compalab.org for more information.

Price (€)		325
Price if online payment (€)		260
Approximate weight (kg)		1

Element	Order of magnitude
Al	0,00x
As	0,00x
C	0,xxx
Ce	0,00x
Co	0,00x
Cr	0,xxx
Cu	0,xxx
Mn	0,xxx
Mo	0,0xx
N	0,00x
Nb	0,00x
Ni	0,xxx
P	0,0xx
S	0,0xx
Sb	0,00x
Si	0,xxx
Sn	0,0xx
Ti	0,0xx
V	0,00x
W	0,0xx
Zr	0,00x

The homogeneity of the samples is assessed a posteriori, on the basis of the participants' results, because of the low and acceptable risk of distributing a non-homogeneous batch of entities subjected to the test.

The experience acquired in organising these interlaboratory comparisons supports the idea of a low risk of the impact that heterogeneity would have on the evaluation of performance.

If this is not the case, the provisions of annex B ISO 13528 are implemented during the assessment.

Note: The methods used by laboratories are very often in-house methods. For minor elements, we may end up with a greater diversity in the performance of the assay methods applied by the participants. This may have an impact on the estimate of the standard deviation of homogeneity (overestimation). This is less true for the major elements.

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