IEC 60404-8-11:2018

Overview

IEC 60404-8-11:2018 is an international standard developed by the International Electrotechnical Commission (IEC) that specifies the requirements for Fe-based amorphous strip materials delivered in the semi-processed state. The standard addresses nominal thicknesses primarily at 0.025 mm, with the option for widths between 0.020 mm and 0.030 mm as agreed between manufacturer and purchaser. These amorphous strips are supplied in coils with as-cast edges and are primarily intended for use in magnetic circuits, particularly in transformer core applications.

The standard defines two major classes of amorphous strip:

• Conventional grades
• High permeability grades

Both classes are suitable for energy-efficient magnetic applications and correspond to Class I1 of IEC 60404-1.

Key Topics

IEC 60404-8-11 addresses essential topics relevant to Fe-based amorphous magnetic materials, including:

• Material Classification: Distinction between conventional and high permeability grades with reference to their specific magnetic and technological properties.
• Dimensions and Tolerances: Specifies nominal thickness and width, with thickness tolerance not exceeding ±0.002 mm and width tolerances depending on strip size.
• Magnetic Properties: Requirements and testing methods for magnetic polarization and specific total loss after standard magnetic annealing.
• Technological Characteristics: Addresses stacking factor, strip tear ductility, and relevant physical properties affecting processability.
• General and Delivery Requirements: Includes production process details, supply forms, delivery conditions (including oxide layer formation), and surface quality expectations.
• Inspection and Testing: Describes inspection procedures, sampling, specimen preparation, and test methodologies, including references to related IEC and ISO standards.
• Purchaser and Manufacturer Information: Outlines the information that must be provided during ordering and after delivery.

Applications

Fe-based amorphous strips covered by IEC 60404-8-11 offer significant advantages for a variety of energy-efficient magnetic applications, especially where low energy loss and high performance are required:

• Transformer Cores: Amorphous strips are widely used in wound core transformers for both 50 Hz and 60 Hz applications due to their reduced core losses compared to traditional grain-oriented electrical steel.
• Magnetic Circuits: The specified materials are suitable for the construction of efficient magnetic circuits in various electrical devices.
• Energy Efficiency: These strips help reduce hysteresis and eddy current losses, contributing directly to global energy savings and lower operational costs.

By using Fe-based amorphous materials standardized under IEC 60404-8-11, manufacturers and engineers can ensure high reliability, consistent magnetic performance, and compliance with international requirements for quality and efficiency.

Related Standards

To ensure comprehensive quality and interoperability, IEC 60404-8-11:2018 references and aligns with a set of related standards concerning magnetic materials and testing protocols:

• IEC 60404-1: Magnetic materials - Classification
• IEC 60404-9: Determination of the geometrical characteristics of magnetic steel sheet and strip
• IEC 60404-16: Measurement of the magnetic properties of Fe-based amorphous strip by means of a single sheet tester
• ISO 404: Steel and steel products - General technical delivery requirements
• ISO 10474: Steel and steel products - Inspection documents
• IEC 60050-121/221: International Electrotechnical Vocabulary for electromagnetism and magnetic materials

These standards provide guidance on material terminology, property measurement, and delivery documentation, helping ensure the consistent performance and global compatibility of Fe-based amorphous strip materials across supply chains and applications.

Keywords: IEC 60404-8-11, Fe-based amorphous strip, magnetic materials, semi-processed, transformer core, magnetic properties, magnetic circuit, international standard, thickness tolerance, stacking factor, inspection procedures