Stress relief techniques are a post-manufacturing process applied to spring materials to reduce residual stresses introduced during fabrication or forming. The process is typically achieved through heat treatment, where the spring is exposed to a controlled temperature for a specific period, which largely depends on the material being treated and the desired outcome. For example, different spring materials, whether standard materials like 300 series stainless sheets of steel or exotic materials like Elgiloy or Hastelloy require tailored stress-relief processes to align with the operational demands of the spring. For designers and engineers, stress relief ensures that spring materials used in applications maintain their structural integrity, perform reliably, and last longer, even in the most challenging environments.
The Importance of Stress Relief
Stresses can lead to premature failure, reduced fatigue life, and dimensional instability of springs, compromising reliability and functionality. Without spring relief, inherent stresses would adversely affect the spring’s mechanical properties, performance, and longevity. On the other hand, stress relief modifies the internal state of spring materials to improve their behavior under load, such as reducing the likelihood of deformation, fatigue failure, or stress-corrosion cracking. The spring’s internal stresses are evenly distributed by undergoing a controlled heat treatment, enhancing its fatigue resistance, corrosion resistance, and overall mechanical stability. This process ensures that springs—whether compression, tension, torsion, or specialty types—perform consistently under load, retain their shape, and withstand repeated use, making them more durable and dependable in critical applications.
How Spring Relief Needs For Selected Spring Materials Are Achieved
Elgiloy
Elgiloy, a cobalt-chromium-nickel alloy, is noted for its exceptional strength, corrosion resistance, and fatigue endurance. Yet, without stress relief, these properties would be compromised by stress concentrations. By applying controlled heat treatment, stress relief optimizes the alloy’s mechanical properties, ensuring dimensional stability and preventing premature failure in high-stress or corrosive environments. This is particularly crucial for Elgiloy springs used in demanding fields like medical devices, aerospace, and chemical processing, where reliability and durability are paramount.
Hastelloy
Hastelloy is the name for a group of corrosion-resistant metal alloys, primarily composed of nickel with varying amounts of molybdenum, iron, cobalt, and chromium. It is renowned for its outstanding corrosion resistance, especially in harsh chemical environments. Stress relief is achieved through controlled heat treatment. The process enhances the material’s fatigue resistance, stabilizes its dimensions, and minimizes the risk of stress-corrosion cracking. This ensures that Hastelloy springs maintain their strength and reliability in demanding applications, such as chemical processing, marine systems, and aerospace, where consistent performance in extreme conditions is critical.
Inconel
Inconel is a family of nickel-chromium-based superalloys known for their exceptional resistance to high temperatures, oxidation, and corrosion. Stress relief processes for Inconel spring materials used in spring applications involve heating the material to a controlled temperature below its recrystallization point. This process dissipates internal stresses without altering the material’s mechanical properties. It also improves fatigue resistance, prevents stress-corrosion cracking, and stabilizes the spring’s dimensions, ensuring consistent performance under extreme conditions such as high temperatures and corrosive environments. Stress relief then maximizes the longevity and reliability of Inconel springs in demanding applications like aerospace, chemical processing, and marine systems.
Carbon Steel
Stress relief processes for carbon steel materials reduce residual stresses introduced during forming, coiling, or machining, which would otherwise lead to fatigue failure or dimensional instability over time. The internal stresses are redistributed by applying controlled heat treatment, typically at temperatures between 150–370°C (300–700°F), thereby improving the spring’s fatigue life and resistance to deformation under cyclic loads. Stress relief also reduces the risk of stress-corrosion cracking and helps maintain the spring’s shape and performance under load. This is essential for carbon steel springs, widely used in many industries, to ensure they deliver reliable and consistent performance in static and dynamic applications.
300 Series Stainless Steels
In 300 series stainless steel materials, stress relief processes relieve internal stresses that can compromise their mechanical performance and durability. Subjecting the material to a controlled heat treatment, typically 300–425°C (570–800°F), reduces these residual stresses, improving fatigue life and dimensional stability and enhancing the material’s resistance to stress-corrosion cracking. This ensures that 300 series stainless steel springs, known for their excellent corrosion resistance and mechanical strength, maintain consistent and reliable performance in demanding applications such as medical devices, automotive components, and marine systems.
17/7 Stainless Steel
This precipitation-hardening stainless steel is regarded for its high strength, excellent fatigue, and corrosion resistance, particularly in demanding environments. The stainless steel material derives its name from its 17% chromium and 7% nickel content, among smaller amounts of aluminum, carbon, and other elements. Stress relief, typically involving a low-temperature heat treatment, stabilizes the material’s mechanical properties and improves its ability to withstand repeated cyclic loads without deformation. This ensures that 17/7 stainless steel springs perform reliably and maintain their structural integrity in critical aerospace, automotive, and chemical applications.
Contact the Experts at James Spring & Wire Company
Whether it is spring material or spring design, stress relief is a post-fabrication technique for maintaining the performance and longevity of springs by minimizing residual stresses introduced during manufacturing. Stress relief techniques ensure optimal spring performance across various spring materials by addressing the internal stresses generated during manufacturing.
James Spring & Wire Company is one of the foremost designers and manufacturers of standard and custom springs, catering to various industries and applications. Whether working with high-performance exotic spring materials or standard spring materials, our engineering team and state-of-the-art capabilities allow us to design and produce the highest-quality springs to meet each project’s unique demands. For more information, contact James Spring to learn how we can help you meet your application requirements and production needs.
