🔩 Tensile testing of metals at elevated temperature (above 35 °C) — Re, Rp, Rm, A, Z; permitted temperature deviations, ways of establishing the extensometer gauge length and testing rate by Method A or B, PN-EN ISO 6892-2

Materials and NDT PN-EN ISO 6892-2

Overview

WHAT THE STANDARD COVERS. We have a preview of ISO 6892-2:2018 (second edition) — from the title page to 10.2.2.3.3 (page 5 of 21); PN-EN ISO 6892-2:2018-08 introduces the text unchanged (IDT). Scope (Clause 1): a method of tensile testing of metallic materials at temperatures higher than room temperature. Principle (Clause 5): the test piece is strained by tensile force to determine one or more mechanical properties, at a temperature higher than 35 °C, i.e. higher than room temperature as specified in ISO 6892-1. Requirements for test pieces, the cross-sectional area (calculated from dimensions at room temperature) and the marking of the gauge length — according to ISO 6892-1; additional examples of test pieces are in Annex A. Definitions: the original gauge length Lo and the percentage elongation after fracture A are measured at room temperature; the reduction of area Z is calculated from dimensions at room temperature; all stresses are engineering stresses; soaking time ts — the time to stabilize the temperature of the test piece before loading. Introduction: two testing-speed methods are described — A, based on strain rates (including crosshead separation rate) with narrow tolerances of ±20 %, and B, based on conventional rate ranges; the influence of the testing speed on the properties is normally greater at elevated temperature than at room temperature, the standard recommends slow strain rates and permits higher ones e.g. for comparison with room-temperature properties. Note to Clause 3: at elevated temperature, unless required by a specification or agreement, properties such as Rr, Ae, Agt, Ag and At are generally not determined.

APPARATUS AND TEMPERATURE (Clause 9 and 10.1–10.2 of the preview). Force-measuring system — ISO 7500-1, class 1 or better. Extensometer — for proof strength ISO 9513 class 1 or better, for other properties class 2 is sufficient; extensometer gauge length at least 10 mm, in the central portion of the parallel length, and the part projecting from the furnace protected from draughts. Permitted deviations of the indicated temperature Ti from the specified temperature T and the maximum temperature variation along the test piece (Table 2): up to 600 °C — ±3 °C and 3 °C, above 600 up to 800 °C — ±4 °C and 4 °C, above 800 up to 1000 °C — ±5 °C and 5 °C, above 1000 up to 1100 °C — ±6 °C and 6 °C; above 1100 °C the deviations are agreed between the parties. With a gauge length below 50 mm a temperature sensor measures each end of the parallel length, with 50 mm or more also its centre; at least one sensor always measures the test piece temperature directly. Temperature-measuring system: resolution 1 °C or better, accuracy ±0.004 T or ±2 °C (whichever is greater), calibration at intervals of not more than one year, traceable to SI. The force zero is set after the testing equipment has been assembled but before the test piece is gripped; a very small tensile force during heating and soaking prevents compressive stresses from thermal expansion. The extensometer gauge length is established in one of four ways — Method 1 (gauge length at room temperature, thermal extension not considered), 2a (nominal gauge length set at test temperature), 2b (reduced gauge length set at room temperature so that the nominal one is reached at test temperature) and 2c (nominal gauge length corrected for thermal expansion); the different ways lead to minor differences in results, so the method is stated in the test report.

STATUS (state on 29 September 2026). The card of PN-EN ISO 6892-2:2018-08 (Polish version) has no "Withdrawn" header — the standard is CURRENT in the PN collection: Polish version published 23-12-2022, 28 pages, price group N, Metallurgy Sector, KT 123 for Testing of Metal Properties, ICS 77.040.10, "Introduces: EN ISO 6892-2:2018 [IDT], ISO 6892-2:2018 [IDT]", "Replaces: PN-EN ISO 6892-2:2011 - English version". The card of PN-EN ISO 6892-2:2011 (English version): "Withdrawn and replaced by PN-EN ISO 6892-2:2018-08", published 18-04-2011, "Withdrawal date: 06-08-2018", 23 pages, "Replaces: PN-EN 10002-5:1998 - Polish version". The PKN search for "PN-EN ISO 6892-2" (29 September 2026) shows only these editions. ISO page: ISO 6892-2:2018 — WITHDRAWN on 3 August 2026 (stage 95.99), replaced by ISO 6892-2:2026 (edition 3, August 2026, 20 pages). According to the foreword of the 2018 edition, it was a minor revision of the 2011 edition (a note after the first sentence of 10.2.1, some references to ISO 6892-1 deleted), while the 2026 edition is a technical revision: revised 9.3 (heating device), wording of 10.3 and 10.4 (Methods A and B), Clause 12 (test report), wording of Annex A and references — including a dated reference to ISO 6892-1:2019. Of the 2026 edition we had only the foreword, introduction and Clauses 1–3.2.

HOW MANY LABORATORIES AND IN WHAT FORM (copy of the accreditation-scope database, data loaded up to 17 September 2026, read on 29 September 2026). All notations of number 6892-2: 15 entries at 11 laboratories (the copy splits two entries of AB 1898 into four records). "PN-EN ISO 6892-2:2018-08" — 9 laboratories; "PN-EN ISO 6892-2" without a year — AB 019 (two entries, with Method B) and AB 120 (flexible scope, together with procedure P/19/IB-01 and PN-EN ISO 6892-1 and 6892-3). The testing-rate method is stated by 6 laboratories: A — AB 001 (in one of two entries), B — AB 019, AB 025, AB 099, AB 1348 and AB 1898. The "Laboratories" tab searches for notations BEGINNING WITH "PN-EN ISO 6892-2" and will show all 11 laboratories — checked with the tab query on the labcoda.pl production server on 30 September 2026: 11. Current scopes on the PCA website (read on 29 September 2026, issues from 18.11.2025 to 28.08.2026): all entries stand in the valid issues, every pair of range numbers from the copy occurs in the current document and no entry is suspended (the suspension footnotes in the scopes of AB 120 and AB 554 concern other entries).

SUBJECT AND RANGES. Metals and alloys, metallurgical products, castings, forgings and metal products — all 11 laboratories; welded joints — AB 019, AB 1348 and AB 1898 (together with PN-EN ISO 4136). Quantities: Re, Rp, Rm, A, Z (at AB 792 also the modulus of elasticity E). Temperature: from (36 – 900) °C (AB 019) and (100 – 650) °C (AB 1898) through "up to 350 °C" (AB 372), "up to 600 °C" (AB 099), "up to 800 °C" (AB 1348), "up to 900 °C" (AB 554), "+ 900 °C" (second entry of AB 001) and "up to 1000 °C" (AB 025, AB 1283) to "up to 1100 °C" (AB 001) and "2000 °F" (AB 792). Force — from 50 kN (AB 1283) to 1000 kN (AB 372).

ALONGSIDE THIS STANDARD. In the same entries: ASTM E21-20 (the American method of tensile testing at elevated temperature) — AB 099, AB 372, AB 792 and AB 1283; PN-EN ISO 6892-1:2020-05 (room temperature) — AB 554 and AB 792; PN-EN ISO 4136 (transverse tensile test of welded joints) — AB 019, AB 1348 and AB 1898; at AB 792 also ASTM E8/E8M-25 and ASTM E111-17 — this entry covers the static tensile test at room and elevated temperature and the modulus of elasticity E. PN-EN ISO 6892-1 and PN-EN ISO 4136 have separate entries in the Knowledge Base. The database copy contains no tensile tests of metals at elevated temperature without this standard (search for "rozciąg…" together with "podwyższ…" in the entry description; hits without this standard concern other products and tests).

WHERE A SEEMINGLY CORRECT RESULT IS EASY TO GET. First — the rate: the standard states plainly that at elevated temperature the rate influences the result more strongly than at room temperature; yield strength from Method A and from Method B are two numbers from different conditions, so a report without the method and rate does not allow comparison. Second — the extensometer gauge length: the four permitted ways (1, 2a, 2b, 2c) give, according to the standard, minor differences in results; without the way stated, elongation and proof strength lose comparability. Third — temperature: what counts is the indicated temperature on the parallel length of the test piece, with the deviations of Table 2, and above 1100 °C there are no standard deviations — they have to be agreed. Fourth — the edition: ISO published a technical revision in August 2026, while the scopes and the PN collection keep the 2018 edition.

WHAT WE DO NOT GIVE. The preview ends at 10.2.2.3.3, so we do not give heating and soaking time (10.2.3), the rates in Methods A and B or the rules for choosing them (10.3–10.6), the determination of properties (Clause 11), the test report (Clause 12), uncertainty (Clause 13) or Annexes A and B; of the 2026 edition we know only the list of changes from the foreword.

Method principle

A metal test piece is heated in a furnace to the specified temperature (above 35 °C), measured by sensors in contact with the parallel length, soaked until stable and pulled to fracture at a strain rate according to Method A (tolerance ±20 %) or at a rate from the conventional ranges of Method B, recording force and extension with an extensometer. The yield strength (Re, Rp) and tensile strength Rm are determined from the curve, and after cooling and measuring the test piece at room temperature — the percentage elongation after fracture A and the reduction of area Z. Stresses are calculated from the cross-section measured at room temperature.

Applications

• Strength properties of metals, metallurgical products, castings and forgings at elevated temperature — in the scopes of 11 laboratories
• Welded joints at elevated temperature — AB 019, AB 1348, AB 1898 (with PN-EN ISO 4136)
• Temperature ranges in accreditation: from 36 °C to 1100 °C (and 2000 °F)

Key parameters

Standard

Standard number

PN-EN ISO 6892-2:2018-08 (wersja polska z 23-12-2022 i wersja angielska; EN ISO 6892-2:2018, ISO 6892-2:2018 IDT)

Title (PL)

Metale — Próba rozciągania — Część 2: Metoda badania w podwyższonej temperaturze

Title (EN)

Metallic materials — Tensile testing — Part 2: Method of test at elevated temperature

Step-by-step procedure

1. Test piece

   Shape, dimensions, cross-sectional area and gauge length according to ISO 6892-1 — measured at room temperature.

2. Force zero and gripping

   Force zero after assembling the equipment, before gripping the test piece; a very small tensile force can be maintained during heating.

3. Extensometer

   Gauge length according to Method 1, 2a, 2b or 2c (10.2.2); the chosen way is recorded in the test report.

4. Heating and soaking

   To the specified temperature with the deviations of Table 2; we DO NOT GIVE the soaking time (10.2.3 outside the preview).

5. Tensile loading

   By Method A or B; we DO NOT GIVE the rates (10.3–10.4 outside the preview).

6. Result

   Re/Rp, Rm, and A and Z after measurements at room temperature; in the report the temperature, the rate method and the way of establishing the extensometer gauge length.

Required equipment and apparatus

Health and safety (OHS)

• The furnace and grips are hot (up to 1100 °C in the scopes) — protection against burns when removing test pieces; warning of the standard: the user establishes the health and safety practices
• SUBSTANTIVE NOTE: the result depends on the rate method (A or B) and the way of establishing the extensometer gauge length — without them in the report two results cannot be compared

Frequently asked questions