GB/T 27691-2017 in English

Background and Significance of the Standard

GB/T 27691-2017 "Wire Rod for Steel Cord" is an important national standard for high-carbon steel wire rod products, mainly used in the manufacture of steel cord in rubber tires. With the rapid development of my country's steel industry and the continuous improvement of industry demand, the original standard GB/T 27691-2011 can no longer meet the current technical requirements. The new standard has been comprehensively optimized in terms of chemical composition, mechanical properties, intrinsic quality and surface quality, further improving product quality and technical level.

Comparative analysis of standard frameworks

Interpretation and application suggestions for core terms

1. Brand and chemical composition management

Wire rod brand consists of the pinyin initials of "cord" (LX) + carbon content lower limit + quality grade. For example: LX70A, LX85B, etc., indicate wire rods for steel cords of different strength levels. The new standard adds two high-level brands, LX85B and LX90B, which are suitable for scenarios with higher strength requirements.

2. Optimization of technical requirements

• Chemical composition:Added control requirements for trace elements such as Cu, Cr, and Ni to ensure material stability.
• Microstructure:The content of troostite is strictly graded according to different grades, and can reach up to 90% or more.
• Non-metallic inclusions:Specify the maximum size and grade requirements of Class A and Class B inclusions to ensure material purity.

3. Test methods and quality inspection

The standard specifies comprehensive inspection items, including chemical analysis, tensile properties testing, microstructure assessment, etc. Users can specify special inspection requirements in the contract according to specific needs, such as grain size or surface oxide scale inspection.

Implementation suggestions

1. Supplier:Choose an enterprise with rich experience in high-carbon steel production to ensure that product quality meets standard requirements.
2. User side:Establish a complete acceptance system and equip professional testing equipment and personnel.
3. Contract negotiation:Specify special technical requirements and confirm them in writing when placing an order.