Consumul de oțel din China pentru elemente de fixare ajunge la 12.5 milioane de tone în 2023 România

Basic components of mechanical manufacturing, such as fasteners, bearings, gears, springs, and tooling, play a crucial role in the quality and reliability of machinery. The production of these essential components relies on steel materials, with an annual output of about 240 million tons, constituting a significant part of the special steel products. As these components are used in various environments, the quality requirements for materials vary accordingly. Therefore, the quality of steel used in these basic components not only determines the level of mechanical manufacturing but also represents the development and standard of the special steel industry.

Fasteners, known as the 'rice  of industry,' are the most widely used basic components. In 2023, China's steel consumption for fasteners reached 12.5 million tons. This steel encompasses almost all steel types, including cold heading steel, alloy structural steel, stainless steel, heat-resistant steel, etc., with standard strength levels ranging from 400 to 1200 MPa. Fasteners are typically manufactured using the cold heading process, requiring the steel to have good cold heading properties. Additionally, depending on the application scenario, the steel for fasteners must also possess properties such as resistance to fatigue failure, delayed fracture, corrosion, high temperature, and low temperature.

The low-cost competition in the fastener industry has driven the extensive replacement of CrMo steel with MnB steel. Currently, the highest grade of fasteners in China's standard (GB/T3098.1-2010) is 12.9, whereas the trend towards mechanical lightweighting demands high-strength fasteners of 14.9 and above. However, achieving this goal requires addressing not only production process issues but also concerns about delayed fracture and fatigue failure.