GOST 9.401-91 PDF

Full title and description

GOST 9.401-91 — Unified system of corrosion and ageing protection. Paint coatings. General requirements and methods of accelerated tests on resistance to the action of climatic factors. The standard establishes general requirements and accelerated test methods used to assess the resistance of paint and varnish coatings on metal and non‑metal surfaces to climatic factors (weathering, humidity, temperature, solar radiation, salt spray and combinations thereof).

Abstract

GOST 9.401-91 specifies principles, test procedures and acceptance criteria for accelerated climatic testing of organic (paint and varnish) coatings intended for different operating conditions and atmospheric types. It defines sample preparation, cyclic test sequences, evaluation criteria (adhesion, corrosion spread from scribe, decorative properties and other degradation modes) and provides guidance on selecting test methods for various macroclimatic regions. The standard excludes aircraft coatings and underwater hull coatings of shipbuilding products.

General information

• Status: Withdrawn / Superseded (not effective).
• Publication date: Approved March 29, 1991; entered into force / published July 1, 1992. (Amendments: e.g. Amendment No.2 — 1998; Amendment No.5 — 2007.)
• Publisher: USSR State Committee for Product Quality and Standards Management (Gosstandart); later maintained in the interstate system of standards.
• ICS / categories: Paints and coatings / corrosion protection — ICS: 25.220.60 (coating materials and paints); related classifier OKS/МКС areas for corrosion of metals (77.060) and standards group 87.020 (protective coatings).
• Edition / version: Original designation GOST 9.401-91 (1991); later editorial changes/amendments in 1998 and 2007; replaced by GOST 9.401-2018.
• Number of pages: Approximately 100–110 pages (commonly cited as 105 pages in published copies).

Scope

This standard applies to paint and varnish coatings on metal and non‑metal products intended for service conditions defined by GOST 9.104 (except category B5) and for atmospheric types classified by GOST 15150. It establishes general requirements and methods for accelerated testing to simulate climatic ageing and weathering. The standard does not apply to coatings for aircraft or to underwater (submerged) parts of shipbuilding products.

Key topics and requirements

• Definitions and general principles for accelerated climatic tests (purpose and limits of accelerated exposure).
• Selection of test methods and sequences for different macroclimatic regions (moderate, cold, tropical, etc.).
• Detailed procedures for common accelerated methods (e.g., cyclic humidity/temperature, salt‑spray, UV/sun simulation, combined cycles) and preliminary screening tests.
• Sample preparation, conditioning, and mounting for reproducible results.
• Acceptance and evaluation criteria: adhesion (cross‑cut), corrosion propagation from scribe, blistering, loss of gloss/colour, decorative properties and quantitative scoring schemes.
• Reporting requirements: test cycles used, exposure durations, measured parameters and consolidated degradation indices used to judge performance.

Typical use and users

GOST 9.401-91 was used by paint and coating manufacturers, quality assurance and independent testing laboratories, materials engineers, procurement and compliance teams, and design offices that needed standardized accelerated climatic testing procedures to assess coating durability for specific service environments. It was referenced in technical specifications, acceptance testing and comparative evaluations of coating systems for industrial, construction and equipment applications (excluding aircraft and submerged ship hulls).

Related standards

Commonly cited companion and predecessor/successor standards include: GOST 9.104 (conditions of service and corrosion categories); GOST 15150 (types of atmosphere and climatic designations); GOST 9.403-80 and GOST 9.407-84 (specific test and rating methods for coatings); GOST 9.402 (surface preparation for painting) and a number of regional GOST documents dealing with specific coatings and test procedures. GOST 9.401-91 was later replaced by GOST 9.401-2018 (updated unified system provisions for accelerated climatic testing).

Keywords

GOST 9.401-91, paint coatings, varnish coatings, accelerated tests, climatic factors, weathering, corrosion protection, adhesion, salt spray, UV exposure, coating durability, macroclimatic regions.

FAQ

Q: What is this standard?

A: GOST 9.401-91 is a national/interstate standard from the former Soviet system that specifies general requirements and accelerated test methods for assessing the resistance of paint and varnish coatings to climatic factors (weathering and related ageing).

Q: What does it cover?

A: It covers principles, sample preparation, specific accelerated climatic test procedures (cyclic humidity/temperature, UV/sun simulation, salt exposure and combined cycles), acceptance criteria (adhesion, corrosion spread, decorative deterioration) and guidance on selecting test regimes according to climatic service conditions. It excludes aircraft coatings and submerged ship hull coatings.

Q: Who typically uses it?

A: Coating manufacturers, independent and in‑house test laboratories, materials and corrosion engineers, procurement and QA/QC personnel, and standards bodies or specifiers who require repeatable accelerated testing methods to evaluate coating performance for different service climates.

Q: Is it current or superseded?

A: GOST 9.401-91 is superseded / withdrawn. It was replaced by a newer edition (GOST 9.401-2018) as part of an update to the unified system of corrosion and ageing protection; copies and registries list the 1991/1992 version as not effective after the replacement.

Q: Is it part of a series?

A: Yes. It is part of the "Unified system of corrosion and ageing protection" series of GOST standards addressing coatings, surface preparation, test methods and corrosion resistance (the 9.xxx group), and is cross‑referenced with standards such as GOST 9.104 and GOST 15150 and many other related GOSTs covering specific test methods and material specifications.

Q: What are the key keywords?

A: Paint coatings, accelerated climatic tests, weathering, corrosion protection, adhesion, salt spray, UV exposure, coating durability, GOST 9.401-91.