Fasteners Manufacturers

Industry knowledge

For high-strength fasteners, how do fastener manufacturers perform heat treatment? How to avoid defects such as quenching cracks during heat treatment?

In the process of manufacturing high-strength fasteners, heat treatment is a crucial link, which is directly related to the mechanical properties, corrosion resistance and service life of the product. As a factory with ISO and PED certification, we are well aware of the importance of heat treatment to ensure the quality of fasteners, and have accumulated rich experience and technical strength in this field. Our products are not only produced in accordance with international standards such as ASTM, JIS, DIN, EN, GOST, but also widely used in many key fields such as oil and gas, petrochemicals, sugar refining, water treatment, seawater desalination, geothermal industry, etc., and exported to dozens of countries and regions such as the United States, Canada, Japan, Germany, France, South Korea, Turkey, etc., and have won wide recognition and trust.
The heat treatment of high-strength fasteners mainly includes three basic stages: heating, insulation and cooling, aiming to improve its mechanical properties such as hardness, strength, toughness, etc. by changing the microstructure of the material. Common heat treatment methods include quenching, tempering, surface hardening, etc.
Quenching: Heat the fasteners to above the austenitizing temperature, keep them warm for a certain period of time, and then quickly cool them to room temperature or a lower temperature to obtain martensite structure, which significantly improves hardness and strength.
Tempering: After quenching, fasteners need to be tempered to eliminate quenching stress, improve plasticity and toughness, and prevent brittle fracture.
Surface hardening treatment: such as carburizing, nitriding, carbonitriding, etc., aims to increase the carbon content or nitrogen content on the surface of the fasteners, improve wear resistance and fatigue strength.
Quenching cracks are one of the most common defects in the heat treatment process. The causes of their occurrence are complex, involving multiple factors such as material composition, heating temperature, cooling rate, workpiece shape and size. We have taken a series of measures to effectively prevent the occurrence of quenching cracks:
Optimize material selection: Select top-quality raw materials that have been fully certified to ensure uniform material composition and low impurity content, and reduce the risk of cracks caused by internal defects in the material.
Precisely control the heating temperature and time: Use advanced temperature control systems to accurately control the temperature and heating time in the heating furnace to ensure uniform austenitization of fasteners, avoid overheating or overburning, and lay a good foundation for subsequent rapid cooling.
Reasonable design of cooling medium and method: According to the material type and size of the fastener, select appropriate cooling medium (such as water, oil, polymer solution, etc.) and cooling method (such as spray cooling, immersion cooling, etc.) to control the cooling speed and avoid stress concentration and cracks caused by too fast or too slow cooling.
Preheating and temperature equalization treatment: For large or complex-shaped fasteners, preheat treatment is performed first to reduce thermal stress during heating; at the same time, temperature equalization treatment is performed before quenching to ensure uniform temperature of the entire workpiece and reduce cracks caused by temperature gradients.
Tempering to relieve stress: Tempering treatment is performed immediately after quenching. Through appropriate tempering temperature and holding time, quenching stress can be effectively released, the toughness of the material can be improved, and the risk of cracks can be further reduced.
Nondestructive testing and quality control: Before and after heat treatment, we use advanced equipment such as spectrometers, metallographic microscopes, and X-ray inspection machines to conduct comprehensive inspections on fasteners, including chemical composition analysis, microstructure observation, internal defect detection, etc., to ensure that every step meets customer requirements and international standards.
Continuous improvement and innovation: We continuously optimize the heat treatment process based on customer feedback and internal test results, and introduce new technologies and equipment, such as vacuum heat treatment, ion nitriding and other advanced technologies, to further improve product quality and production efficiency.
Company advantages
Technical strength: With a professional team of heat treatment engineers and advanced heat treatment equipment, we can customize heat treatment solutions according to customer specific needs to meet the special performance requirements of high-strength fasteners.
Quality control: Implement a strict quality management system, from raw material procurement to finished product delivery, each process is strictly inspected to ensure the high performance and durability of the product.
Service response: Provide fast-response customer service, including technical consultation, sample testing, production progress reports, etc., to ensure that customer needs are met in a timely manner.
Global network: With extensive international export experience, we can quickly adapt to the standards and regulations of different countries and regions and provide customers with global supply chain solutions.
In terms of heat treatment of high-strength fasteners, we rely not only on advanced technology and equipment, but also on a deep understanding of the process and an unremitting pursuit of quality. Through these measures, we effectively avoid the occurrence of defects such as quenching cracks, and provide customers with high-quality, high-performance fastener products to help them operate stably in various harsh environments.