SIST EN 1780-2:2004

Overview

SIST EN 1780-2:2004 is a European standard developed by CEN that specifies a chemical symbol based designation system for alloyed aluminium and aluminium alloys. This standard is focused on the precise and consistent identification of aluminium ingots intended for remelting, master alloys, and castings. It serves as a critical guideline for manufacturers, suppliers, and quality inspectors in the aluminium industry, ensuring clear communication about alloy compositions across European markets.

Unlike unalloyed aluminium, which is designated under EN 576, or the numerical designation system in EN 1780-1, EN 1780-2 applies a system using international chemical symbols combined with nominal content values. This system facilitates the precise specification and classification of materials based on their chemical makeup.

Key Topics

• Chemical Symbol Based Designation
  Alloys are identified by the symbol "Al" for aluminium, followed by chemical symbols of key alloying elements. These are arranged in order of decreasing nominal content, using mass percentage figures to indicate content levels.
  • Example: EN AB-Al Si5Cu3 (Aluminium alloy with 5% Silicon and 3% Copper)
• Rules for Similar Compositions
  When alloys have similar chemical compositions, additional identifiers are used to differentiate them:
  • Rounded nominal contents (e.g., Si7Mg0.3 vs. Si7Mg0.6)
  • Indication of main impurities in parentheses (e.g., Si10Mg(Cu))
  • Use of alphabetic suffixes to indicate registration date when needed (e.g., Si12(a), Si12(b)).
• Master Alloys Identification
  Master alloys are differentiated with suffixes (A) or (B) to indicate low or high impurity levels respectively.
• International Chemical Symbols
  The standard uses internationally recognized chemical symbols to represent alloying elements such as Si (Silicon), Cu (Copper), Mg (Magnesium), Fe (Iron), and others listed in the annex.

Applications

The EN 1780-2 designation system is essential for:

• Aluminium remelting industries, helping clearly define input materials for recycling and alloy preparation.
• Master alloy production, where impurity levels and specific compositions must be accurately communicated to users.
• Casting operations, providing standard chemical identifications for cast aluminium products to meet mechanical and chemical properties specifications.
• Quality control and certification, enabling consistent alloy classification across European markets and ensuring materials meet designated standards.
• Supply chain management, helping suppliers and buyers accurately specify and order aluminium alloys based on chemical composition.

By standardizing alloy designations, EN 1780-2 reduces errors, improves traceability, and supports international trade compliance within the aluminium industry.

Related Standards

• EN 576: Unalloyed Aluminium Ingots for Remelting
  Specifies designation rules for pure aluminium, which is outside the scope of EN 1780-2.
• EN 1780-1: Numerical Designation System
  An alternative system that uses numerical codes for designation instead of chemical symbols.
• EN 1780-3: Writing Rules for Chemical Composition
  Defines protocols for reporting chemical compositions to ensure uniformity and accuracy.
• EN 575: Master Alloys produced by Melting - Specifications
  Provides detailed chemical requirements that complement the designation rules in EN 1780-2.
• EN 1676: Alloyed Ingots for Remelting - Specifications
  Details the chemical and physical criteria for alloyed aluminium ingots used in remelting.
• EN 1706: Aluminium and Aluminium Alloys - Castings - Chemical Composition and Mechanical Properties
  Covers standards pertinent to cast aluminium alloys linked to the designation system.

By aligning industry practices under EN 1780-2, manufacturers and users contribute to improved material quality assurance, harmonized alloy identification, and regulatory compliance across the European aluminium market. This standard plays a foundational role in material traceability and is vital for metallurgical consistency in aluminium production and application.