GOST 1778-70 PDF

Full title and description

ГОСТ 1778-70. Сталь. Металлографические методы определения неметаллических включений — Steel. Metallographic methods for the determination of nonmetallic inclusions (standard includes Amendments No. 1 and No. 2; national adoption aligned with ISO 4967).

Abstract

Standard specifying metallographic (micrographic) procedures for detecting, classifying and quantifying non‑metallic inclusions in steels and steel products. It defines sampling and specimen preparation, observation methods (standard diagrams / JK‑ or ASTM‑style comparison and linear/counting methods), classification groups for inclusion types (oxides, sulfides, silicates, nitrides etc.), scoring (grading) procedures and calculation of average inclusion scores with associated error limits. The USSR edition was harmonized with ISO 4967.

General information

• Status: Replaced / superseded — formally cancelled in national lists and subsequently replaced by a modern revision ГОСТ 1778-2022 (new GOST published 2023).
• Publication date: Approved 28 September 1970; date of introduction (effective date) 1 January 1972. (Original edition: ГОСТ 1778-70; later reissues with amendments).
• Publisher: Approved by Gosstandart (State Committee for Standards of the USSR); official printed edition issued by Издательство стандартов (Moscow, official 1971 edition).
• ICS / categories: 77.080.20 (Steels; metallurgy — metallography / test methods).
• Edition / version: Original designation ГОСТ 1778-70 (linked to ISO 4967); published with Amendments No.1 and No.2 in subsequent information releases.
• Number of pages: 30 pages (PDF of the standard as archived).

Scope

Applies to steel and steel‑alloy products where metallographic assessment of non‑metallic inclusions is required for quality control, acceptance testing or research. The standard sets out which specimen types and sections to take for different product forms (bars, billets, plates, pipes, castings), required polished area size, observation magnification/field size, choice of diagram sets or image‑analysis alternative procedures, and rules for recording and reporting inclusion evaluation results.

Key topics and requirements

• Sampling and specimen selection rules for different product forms (bars, billets, pipes, plates, castings) and required minimum polished area (example: not less than 200 mm² for a single polished surface).
• Specimen preparation: cutting, mounting, polishing and etching precautions to avoid deformation, tearing or contamination of inclusions.
• Observation methods: use of standard diagrams (JK/ASTM style) at specified magnification (typical reference magnification 100× with field diameter ~0.8 mm) and alternative linear/counting procedures.
• Classification of inclusion morphology and types (oxide, sulfide, silicate, nitride, etc.) and grouping rules (multi‑group scheme used for grading).
• Grading/scoring system (multi‑point scale) and formulas for computing the average inclusion score for a melt/lot together with permissible error (statistical treatment of multiple specimens).
• Annexes/recommended methods describing which metallographic technique is preferred for particular steel types and production methods (control vs. research methods).

Typical use and users

Used by metallurgical laboratories, production quality control teams at steel producers and foundries, materials testing laboratories, inspection bodies, failure‑analysis specialists, and design/acceptance engineers specifying cleanliness requirements for critical structural, tooling or high‑purity steel products. The method supports acceptance testing, process control and research into inclusion effects on mechanical properties.

Related standards

ISO 4967 (international micrographic method for non‑metallic inclusion assessment — historical and later editions including 1979 and 2013), successor national standard ГОСТ 1778-2022 (modern revision), and various ASTM/BS/EN standards on inclusion assessment and metallographic specimen preparation (for example ASTM E45 and related metallography preparation standards).

Keywords

non‑metallic inclusions, metallography, micrographic method, steel cleanliness, inclusion classification, JK diagrams, specimen preparation, inclusion scoring, ГОСТ 1778-70, ISO 4967.

FAQ

Q: What is this standard?

A: ГОСТ 1778-70 is an interstate (USSR) standard that specifies metallographic (micrograph‑based) methods for detecting, classifying and quantifying non‑metallic inclusions in steels; it was aligned with ISO 4967.

Q: What does it cover?

A: It covers sampling rules for different product forms, specimen cutting/mounting/polishing, observation procedures (standard diagram comparison and linear/counting methods), classification of inclusion types and morphology, grading/scoring procedures and statistical treatment of results, plus annexed recommendations for method selection.

Q: Who typically uses it?

A: Metallurgical/QA laboratories, steel manufacturers, inspection agencies, research institutes and engineers responsible for material acceptance and quality control who need to assess steel cleanliness and non‑metallic inclusion content.

Q: Is it current or superseded?

A: The 1970 edition (ГОСТ 1778-70) has been superseded — it was listed in cancellation/transition actions and replaced by a modern revision ГОСТ 1778-2022 (new national standard published/implemented in 2023). Users should apply ГОСТ 1778-2022 or the current applicable national/international standard for up‑to‑date requirements.

Q: Is it part of a series?

A: It continues earlier national practices (replacing ГОСТ 1778-62) and is linked to the international ISO series on inclusion assessment (ISO 4967 and its later revisions). The topic sits within the broader metallurgy/metallography standards cluster (ICS 77.080.20).

Q: What are the key keywords?

A: Inclusions, non‑metallic inclusions, metallographic method, micrograph, steel cleanliness, JK diagrams, inclusion grading, specimen preparation, ГОСТ 1778, ISO 4967.