🔩 Manual pulse-echo ultrasonic testing of austenitic and austenitic-ferritic stainless steel forgings (four types of forgings, excluding closed die forgings and turbine rotor and generator forgings) — written procedure, A-scan instrument, probes 0,5–6 MHz (normal-beam with transducer diameter 10–40 mm, angle-beam 35–70°, dual-element for the near-surface zone), reference blocks with at least three reflectors for DAC, testing after final heat treatment, surface roughness depending on the quality class, PN-EN 10228-4

Materials and NDT PN-EN 10228-4

Overview

WHAT THE STANDARD COVERS. Scope from the PKN catalogue card of PN-EN 10228-4:2016-07 (English version; scope in Polish on the card), in full (our translation of the Polish card text): “This European Standard describes techniques used for manual pulse-echo ultrasonic testing of forgings made of austenitic and austenitic-ferritic stainless steels. Mechanized scanning methods, such as immersion testing, agreed between supplier and purchaser may also be used. This part of EN 10228 applies to four types of forgings defined by their shape and method of production. Types 1, 2 and 3 cover forgings of simple shape, type 4 of complex shape. This part of EN 10228 does not apply to: – closed die forgings; – rotor and generator forgings. Ultrasonic testing of ferritic and martensitic steel forgings is the subject of Part 3 of this European Standard”. We read the text of the standard in the preview of SIST EN 10228-4:2016 (text of EN 10228-4:2016) from the cover to clause 10.3 (page 9); we do not have Clauses 11–16 (sensitivity setting, scanning, quality classes, criteria, sizing, test report) or the annexes.

ACCORDING TO THE TEXT OF EN 10228-4:2016 (foreword, Clauses 1–10.3). The standard was prepared by ECISS/TC 111 “Steel castings and forgings” (secretariat AFNOR); CEN approved it on 3 October 2015; it supersedes EN 10228-4:1999, and the technical changes are listed in Annex C. The EN 10228 series: Part 1 — magnetic particle inspection, Part 2 — penetrant testing, Part 3 — ultrasonic testing of ferritic and martensitic forgings, Part 4 — ultrasonic testing of austenitic and austenitic-ferritic forgings. Scope (Clause 1, as on the card; the EN text speaks of turbine rotor and generator forgings). References: EN 1330-1, EN 1330-4 (terminology), EN 12668-1, -2, -3 (instruments, probes, combined equipment), EN ISO 2400 (calibration block No. 1), EN ISO 9712, EN ISO 16811 (sensitivity and range setting), EN ISO 16827 (characterization and sizing of discontinuities). Mandatory information (Clause 4) — to be agreed at enquiry or order: a) manufacturing stage(s); b) volume to be tested and grid or 100 % scanning coverage; c) near-surface testing; d) quality class or classes and zones; e) recording and acceptance criteria if different from Tables 5, 6 and 7; f) special scanning coverage, equipment or couplant; g) scanning technique if not manual; h) sizing techniques for extended discontinuities; i) technique for setting sensitivity; j) presence of the purchaser; k) submission of the written procedure for approval; l) testing with angle-beam probes; m) remaining requirements for complex forgings (type 4). Procedure (Clause 5): testing according to a written procedure — a product specification, a procedure written for the application, or this standard supplemented with details; it contains at least: description of forgings, reference documents, operator qualification, manufacturing stage, zones by quality class, preparation of surfaces, couplant, description and calibration of equipment, scanning plan, sequence of operations, recording levels, characterization of discontinuities, acceptance criteria and test report. Personnel (Clause 6): according to EN ISO 9712. Equipment (Clause 7): A-scan instrument according to EN 12668-1; probes for initial detection according to EN 12668-2 (supplementary ones need not); contouring according to EN ISO 16811; nominal frequency 0,5–6 MHz; normal-beam probes — effective transducer diameter 10–40 mm; angle-beam (transverse waves) — 35–70°, effective transducer area 20–625 mm²; for the near-surface zone — dual-element probes; calibration blocks according to EN ISO 2400; reference blocks — when sensitivity is set by the distance-amplitude curve (DAC) technique or discontinuities are sized relative to reference reflectors; surface condition of the block as the object, at least three reflectors covering the whole depth tested; block from an excess length of the object, from a part of the same material and heat treatment condition, or from a part with similar acoustic properties (judged by a level 2 person); blocks are not used in the DGS technique except to check the accuracy of a DGS diagram; reflector sizes other than in Tables 5 and 6 — with corresponding correction of sensitivity; the same couplant for range and sensitivity setting, scanning and assessment (examples: water with or without corrosion inhibitor or softener, grease, oil, glycerol, cellulose paste), removed after testing if it harms subsequent operations. Calibration (Clause 8): combined equipment (instrument and probes) according to EN 12668-3. Stage (Clause 9): after final heat treatment unless otherwise agreed (e.g. latest possible stage for areas that cannot be tested after the treatment); cylindrical and rectangular forgings to be bored should preferably be tested before boring. Surface (Clause 10): free of paint, non-adhering scale, dry couplant and irregularities; in the machined condition Ra ≤ 12,5 µm for quality classes 1 and 2, Ra ≤ 6,3 µm for class 3 (Table 1); in the as-forged condition — acceptable if the required class is achievable; when full testing is not practicable — shot blasting, sand blasting or grinding to maintain coupling; note: usually only class 1 is achievable; this is where the part we read ends.

STATUS (cards as of 02.10.2026). The card of PN-EN 10228-4:2016-07 (English version, published 22-07-2016, 27 pages, price group N) has no “Withdrawn” header: Metallurgy Sector, KT 123 Testing of Metal Properties, ICS 77.140.85, 77.040.20, “Introduces: EN 10228-4:2016 [IDT]”, “Replaces: PN-EN 10228-4:2000 – Polish version”. PN-EN 10228-4:2000 (Polish version, published 29-12-2000, 22 pages; introduced EN 10228-4:1999) — “Withdrawal date: 22-07-2016”, replaced by PN-EN 10228-4:2016-07.

HOW MANY LABORATORIES AND IN WHAT FORM (copy of the accreditation scope database, data up to 17.09.2026, read on 02.10.2026). The number 10228-4 appears in 11 records at 7 laboratories: AB 001, AB 313, AB 608, AB 904, AB 1336, AB 1505, AB 1827. In the current scopes on the PCA website (read on 02.10.2026, issues from 23.04.2025 to 02.09.2026) the number appears at all 7: “PN-EN 10228-4:2016-07” at AB 001 (five places in the scope, with an asterisk — tests on whose results the laboratory issues opinions and interpretations), AB 313, AB 1336, AB 1505 and AB 1827; without the year at AB 608 and AB 904 (with the mark “E” — flexible scope). No row is set in bold italics. The “Laboratories” tab searches for entries BEGINNING WITH “PN-EN 10228-4” and shows all 7 laboratories — checked with a query of the tab on the production server labcoda.pl on 02.10.2026.

WHAT THE LABORATORIES TEST (items in the PCA scopes). Steel forgings — “material discontinuities”, “internal discontinuities”, “discontinuities”, ultrasonic method; always in one item with PN-EN 10228-3 (ferritic and martensitic forgings) and usually with PN-EN ISO 16810 (general principles), at AB 904 also PN-EN ISO 16811 and 16827, next to PN-EN 10160 (flat products) and PN-EN 12680-1 (castings).

WHERE A SEEMINGLY CORRECT RESULT IS EASY TO GET. Material: austenitic and austenitic-ferritic forgings are tested according to Part 4, ferritic and martensitic ones — according to Part 3; these are two different standards in the same scope item. Reference block: it must have the surface condition and acoustic properties of the forging tested (preferably from an excess length or of the same material and heat treatment) — a block of a different grade changes the sensitivity. DGS: reference blocks are not used in this technique except to check the diagram. Surface: quality class 3 requires Ra ≤ 6,3 µm; on an as-forged surface usually only class 1 is achievable. Couplant: the same for setting, scanning and assessment. Stage: testing after final heat treatment, forgings to be bored preferably before boring. Agreements: without an agreed quality class, coverage and criteria (Clause 4) the result has no reference.

WHAT WE DO NOT GIVE. We do not have the clauses on sensitivity setting, scanning, quality classes, recording and acceptance criteria (Tables 5–7), sizing and the test report, or Annexes A and C — so we do not give recording levels, acceptance criteria or the changes from the 1999 edition.

Method principle

An austenitic or austenitic-ferritic steel forging is scanned manually with an ultrasonic probe (pulse echo) through a couplant; echoes from discontinuities are compared with a DAC curve from a reference block or with a DGS diagram and assessed according to the agreed quality class.

Applications

• Austenitic and duplex stainless steel forgings — 7 laboratories in the PCA scopes
• Forgings of simple shape (types 1–3) and complex shape (type 4) in acceptance testing by quality class
• Testing of cylindrical and rectangular forgings before boring

Key parameters

Standard

Standard number

PN-EN 10228-4:2016-07 (wersja angielska; EN 10228-4:2016 IDT)

Title (PL)

Badania nieniszczące odkuwek stalowych — Część 4: Badanie ultradźwiękowe odkuwek ze stali nierdzewnych austenitycznych i austenityczno-ferrytycznych

Title (EN)

Non-destructive testing of steel forgings — Part 4: Ultrasonic testing of austenitic and austenitic-ferritic stainless steel forgings

Step-by-step procedure

1. Agreements and procedure

   13 items of Clause 4 (including quality class, coverage, criteria) and a written procedure according to Clause 5. PN-EN 10228-4:2016-07 current (cards as of 02.10.2026).

2. Equipment

   Instrument and probes according to EN 12668; calibration of combined equipment according to EN 12668-3; reference block for DAC.

3. Stage and surface

   After final heat treatment; surface free of paint and scale, Ra ≤ 12,5 µm (classes 1, 2) or ≤ 6,3 µm (class 3).

4. Testing

   Manual scanning with normal-beam probes (and angle-beam or dual-element, if agreed) with the same couplant; sensitivity by DAC or DGS.

5. Assessment

   Recording and assessment of indications according to the agreed quality class and the criteria of the standard; removal of couplant if harmful.

Required equipment and apparatus

Reagents, media and consumables

Health and safety (OHS)

• The part of the standard we read contains no safety warnings; heavy forgings — safe support and handling; couplants (oil, grease) — risk of slipping
• TECHNICAL NOTE: Part 4 concerns austenitic and duplex steels — for ferritic and martensitic ones Part 3 applies; the reference block must correspond to the material of the forging

Frequently asked questions