Ultrasonic testing of steel flat product of thickness equal or greater than 6 mm (reflection method)

EN 10160:1999
Ultrasonic testing of steel flat product of thickness equal orgreater than 6 mm (reflection method)

EUROPEAN STANDARD

NORME EUROPEENNE

EUROPAISCHE NORM

ICS 77.040.20; 77.140.50
English version
Ultrasonic testing of steel flat product of thickness equal orgreater than 6 mm (reflection method)
Controle ultrasonore des produits plats en acier d'epaisseuregale ou superieure a 6 mm (methode par reflexion)
UltraschallprOfung von Flacherzeugnissen aus Stahl miteiner Dicke groBer Oder gleich 6 mm (Reflexionsverfahrent
This European Standard was approved by CEN on 3 March 1999.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or to any CEN member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom.

EUROPEAN COMMITTEE FOR STANDARDIZATION

Central Secretariat: rue de Stassart, 36 B-1050 Brussels

Contents
Foreword 3
1 Scope 4
2 Normative references 4
3 Terms and definitions 4
4 Principle 5
5 Personnel 5
6 Apparatus 5
7 Coupling conditions - Surface condition of the flat product 7
8 Scanning plan 7
9 Procedure 8
10 Acceptance criteria 9
11 Test report 9
Annex A (informative) List of equivalent terms in several european languages 13

Foreword
This European Standard has been prepared by Technical Committee ECISS/TC 2 "Steel - Physico-chemical and non-destructive testing", the secretariat of which is held by AFNOR.
This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by January 2000, and conflicting national standards shall be withdrawn at the latest by January 2000.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom.

1 Scope
This European Standard describes a method for the ultrasonic testing of uncoated flat steel product for internal discontinuities. It is applicable to flat product in nominal thickness range of 6 mm to 200 mm of non-alloyed or alloyed steel, excluding austenitic or austenoferritic steels. However, this standard may be applied to the latter types of steels provided that the difference between the amplitude of the noise signal and that of the echo detection threshold is sufficient for the limit fixed.
This standard also defines four quality classes for the flat product body (classes S o , S - Other methods of testing (e.g. by transmission) or other test equipments may be used at the manufacturer's discretion provided that they give identical results to those obtained under the conditions of this standard. In the event of a dispute, only the method defined in this standard shall prevail.
Testing of flat product of thickness less than 6 mm may be the subject of special agreements between the parties concerned.
The inspection is normally carried out in the place of production or on the premises of the supplier. If specified on the order, the inspection may take place in the presence of the purchaser or his representative .
A list of equivalent terms in several European languages is given in annex A.
2 Normative references
This European Standard incorporates by dated or undated reference, provisions from other publications. These normative references are cited at the appropriate places in the text and the publications are listed hereafter. For dated references, subsequent amendments to or revisions of any of these publications apply to this European Standard only when incorporated in it by amendment or revision. For undated references the latest edition of the publication referred to applies.
EN 473, Qualification and certification ofNDT personnel - General principles
prEN 1330-4, Non destructive testing - Terminology - Part 4 : Terms used in ultrasoning testing
3 Terms and definitions
For the purposes of this European Standard, the definitions given in prEN 1330-4 and the following definitions apply:
3.1
internal discontinuity
any imperfection lying within the thickness of the flat product, e.g planar or laminar imperfection, single-plane or multi-plane inclusion bands or clusters
NOTE It is referred in the text as discontinuity.
3.2
defect
unacceptable internal discontinuity, i.e. exceeding the specified maximum size or population density limits
3.3
Population density

the number of individual internal discontinuities of a size greater than a specified minimum size and less than a specified maximum size per specified area of body or length of edge zone
In this case, all steps should be taken to ensure that the production process is not disturbed.
3.4
manual and assisted manual testing
testing by an operator applying an ultrasonic probe, or probes, to the flat product surface, manually executing the appropriate scanning pattern on the flat product surface and visually assessing ultrasonic signal indications on the electronic equipment screen either by direct viewing or by built-in signal amplitude alarm devices
3.5
automatic and semi-automatic testing
testing using a mechanized means of applying the ultrasonic probe or probes to, and executing the appropriate scanning pattern on the flat product surface, together with ultrasonic signal indication evaluation by electronic means. Such testing can be either fully automatic with no operator involvement, or semi-automatic when the operator performs basic equipment operation functions
4 Principle
The method used is based on the reflection of ultrasonic waves (generally longitudinal), the mean direction of which is perpendicular to the surface of the product. The examination consists of:
a) locating any discontinuity by comparing the amplitude of the discontinuity echo with the amplitude of the echo of a flat-bottomed hole of a given diameter and located at the same depth as the discontinuity.
NOTE Only those discontinuities giving an echo at least equivalent in amplitude to that of the echo obtained with the reference flat-bottomed hole are taken into consideration ;
b) then determining its area, the contour of the discontinuity being defined by the positions of the centre of the probe corresponding to a echo amplitude of half the maximum amplitude of the discontinuity under consideration (6 dB method). -
The examination is carried out during the first ultrasonic scan for all the flat product thicknesses and from one side only.
5 Personnel
Testing is carried out by qualified personnel under the responsability of a level 3 individual certified in accordance with EN 473.
6 Apparatus
6.1 Description
The detection apparatus shall be equipped with an oscilloscope screen allowing the path of the ultrasonic waves in the flat product to be followed. The oscillograms shall be clearly visible, the peaks corresponding to the successive echoes being sharp and very clear ; the apparatus shall be suitably calibrated and shall be equipped with an amplifier marked in decibels.
Both ultrasonic testing apparatus with display monitor and amplifier control graduated in dB, or apparatus without display monitor can be used. Apparatus without display monitor shall be able to carry out automatic amplitude testing and evaluation and their unit of measurement shall be calibrated in dB.
It shall be possible to regulate amplification, power and time base.
The apparatus includes at least one probe which may be either a probe with a single transducer serving for both emission and reception (single probe) or a double transducer probe (separate emission-reception transducers). The mean direction of the waves emitted and received shall be perpendicular to the surface of the product.
The probe shall have a frequency and dimensions such that the required sensitivity can be guaranteed throughout the extent of the test field.
The single probes shall be such that their dead zone is as small as possible, i.e. 15 % of the flat product thickness or 15 mm whichever is the smaller. The focusing zone of the double transducer probes shall be adapted to the thickness of the flat product.
The main dimensions of probes are 10 mm to 25 mm in diameter and the probes shall have a nominal frequency in the range of 2 MHz to 5 MHz. Probes of larger dimension and of a nominal frequency that is outside the range of 2 MHz to 5 MHz may be used for automatic or semi-automatic testing and/or when the flat product exhibits high attenuation provided that the main requirements of this standard are met.
The type of the probe depends on the thickness of the flat product as given in table 1 :
Table 1 - Type of probe
Nominal thickness of the flat product (e) or depth of any discontinuity zone mm Type of probe 6 < e < 60 Double transducer probe 60 < e < 200 Single or double transducer
probe a > b ) a) In the event of a dispute, the type of probe to be used shall be the subject of an agreement.
b) Where automatic testing is carried out using immersion or water column techniques, it is permissible to use single crystal probes < 60 mm thick.
The probe may be either hand held, or mounted on a cont