GOST 7268-82 PDF

Full title and description

GOST 7268-82 — Steel. Method for determination of ability to mechanical ageing by impact bend testing (Рус.: Сталь. Метод определения склонности к механическому старению по испытанию на ударный изгиб). A short procedural standard that specifies sample selection, preparatory cold-deformation and artificial ageing regimes, and Charpy-type impact-bending test procedures used to assess the tendency of steel products to mechanical (age) embrittlement.

Abstract

This standard defines a laboratory test method to determine the tendency of steels (sheet, strip, shaped and long products) to mechanical ageing by comparing impact-bending energy or impact toughness before and after controlled cold plastic deformation followed by artificial ageing. The method prescribes sampling rules, deformation and ageing parameters, test temperatures and evaluation criteria (work of impact or impact toughness) and references required test equipment and related standards.

General information

• Status: Active / In force (document retained in current collections of national standards).
• Publication date: Approved 3 September 1982; introduced into force 1 January 1983 (with Amendment No.1 approved November 1986).
• Publisher: State Committee for Standards (Gosstandart / Interstate standard — Межгосударственный стандарт, Soviet origin).
• ICS / categories: Metallurgy — OKS/ICS class 77.040.10 (metallurgical testing / impact testing area).
• Edition / version: Original designation GOST 7268-82 (replacing GOST 7268-67); includes Amendment No.1 (1986); reprints/reissues appear in collections (1998 reissue noted in archival sources).
• Number of pages: 4 (concise procedural standard).

Scope

Specifies a laboratory method for determining the tendency of steel to mechanical ageing (embrittlement) by impact-bending (Charpy-type) testing. Applies to sheet and strip mill products with nominal thickness not less than 5 mm, and to shaped and long products unless other procedures are specified in product technical documentation. The standard covers sampling, preparation of test blanks, cold plastic deformation regimes, artificial ageing (temperature/time), impact testing conditions and interpretation of results.

Key topics and requirements

• Sampling: procedures for selecting test blanks from production material (refers to general sampling rules for rolled products).
• Deformation regime: cold plastic deformation by tensile stretching to produce a residual elongation of (10 ± 0.5)% for tensile deformation (alternative compression deformation with residual 7 ± 0.7% allowed when specified).
• Preparatory dimensions: recommended blank lengths (e.g., nominal lengths 120, 160 mm or longer) and positioning of deformation relative to grips.
• Artificial ageing: typical ageing procedure given as heating to (250 ± 10) °C with hold for 1 hour followed by air cooling (unless other temperatures/times are specified by product documentation).
• Impact testing: Charpy-type impact-bending tests carried out in accordance with the referenced impact test standard; test temperature is specified by product documentation or defaulted to 20 °C.
• Measured quantities and evaluation: determination of work of impact or impact toughness before and after deformation/ageing and calculation of an ageing-tendency indicator by comparison with the initial state.
• Referenced equipment and metrology: requirements for testing machines, heating devices, thermocouples and measuring instruments (references to applicable GOSTs for machines and measurement accuracy).

Typical use and users

Used by metallurgical laboratories, quality control and R&D departments of steel producers, inspection and certification bodies, materials testing laboratories, and designers/specifiers concerned with long-term performance of low-alloy and low-carbon steels. Typical applications include batch acceptance testing, failure analysis, research into ageing phenomena and verification of product conformity where susceptibility to mechanical ageing is a concern.

Related standards

Standards commonly referenced together with GOST 7268-82 include general sampling rules for rolled products, Charpy/impact testing standards and equipment specifications — for example: GOST 7564 (sampling of rolled products), GOST 9454 (impact-bending test procedures/Charpy), GOST 28840 (testing machine requirements) and other metrology and instrument standards referenced in the method. GOST 7268-82 replaced the earlier GOST 7268-67; the method also corresponds to regional/SEV practice stated in the standard's references.

Keywords

steel; mechanical ageing; ageing tendency; embrittlement; impact bending; Charpy test; impact toughness; work of impact; artificial ageing; cold deformation; sampling; test method; GOST 7268-82.

FAQ

Q: What is this standard?

A: GOST 7268-82 is a procedural standard that specifies how to determine the tendency of steel to mechanical ageing (embrittlement) using impact-bending (Charpy-type) tests after controlled cold deformation and artificial ageing.

Q: What does it cover?

A: It covers sampling, preparation of deformed and control specimens, specified deformation magnitudes (typical residual elongation values), artificial ageing regimes (typical: 250 ± 10 °C for 1 hour), impact test conditions and the method to evaluate the ageing tendency by comparing impact energy or impact toughness before and after treatment.

Q: Who typically uses it?

A: Metallurgical and materials testing laboratories, steelmakers, quality assurance and inspection bodies, certification organisations and designers or engineers assessing long-term toughness and susceptibility to ageing in steel products.

Q: Is it current or superseded?

A: The standard GOST 7268-82 was approved 3 September 1982 and introduced 1 January 1983; it replaced GOST 7268-67 and includes Amendment No.1 (1986). It is retained in archival/current collections of national standards as the procedural method for this test (status reported as in force in standard registries and libraries).

Q: Is it part of a series?

A: It is a stand-alone method standard within the metallurgical testing suite but is normally used together with related standards for sampling, Charpy impact testing and testing-machine/equipment metrology. Historically it is aligned with regional (COMECON/SEV) practice and replaced an earlier edition (1967).

Q: What are the key keywords?

A: Mechanical ageing, embrittlement, cold deformation, artificial ageing, impact bending, Charpy, impact toughness, work of impact, steel testing, GOST 7268-82.