Research on Residual Stress Relief Technologies for Stamped Parts

Residual stress in stamped parts, generated during plastic deformation, can lead to dimensional instability, reduced fatigue life, and increased susceptibility to corrosion. Research into residual stress relief technologies focuses on developing efficient methods to reduce or eliminate these stresses without compromising part geometry or material properties.

Thermal-based technologies are widely studied and applied. Stress-relief annealing involves heating the stamped part to a temperature below its recrystallization point (typically 150–300°C for aluminum alloys and 500–600°C for steels) and holding it for a specified duration before slow cooling. This process allows the material’s internal structure to relax, releasing residual stresses. The key is to optimize temperature and time parameters: excessive heating can cause grain growth, weakening the material, while insufficient heating leaves significant stresses unaddressed. Recent advancements in controlled atmosphere annealing, using inert gases to prevent oxidation, have improved the effectiveness of this method for high-precision parts.

Mechanical stress relief methods are also gaining attention. Shot peening, a surface treatment where small spherical particles (shots) are blasted at the part’s surface, induces compressive residual stresses that counteract the tensile stresses from stamping. This not only relieves existing stresses but also enhances fatigue resistance. Laser peening, a more precise alternative, uses high-energy laser pulses to generate shock waves on the surface, creating deeper and more uniform compressive stresses—ideal for critical components like turbine blades or automotive suspension parts.

Vibratory stress relief (VSR) is a non-thermal, energy-efficient technology that applies controlled vibrations to the part at its natural frequency. This induces microplastic deformation, allowing residual stresses to dissipate over time. VSR is particularly useful for large or complex-shaped parts that are difficult to heat uniformly, such as stamped metal frames or structural panels. Recent research has focused on optimizing vibration parameters (amplitude, frequency, duration) using computer simulations to target specific stress concentrations, improving the efficiency of the process.

Advanced hybrid technologies, combining thermal and mechanical methods, are emerging as promising solutions. For example, combining low-temperature annealing with ultrasonic vibration can accelerate stress relief in high-strength steels, reducing processing time while maintaining material strength. These innovations are critical for industries requiring both high precision and durability, such as aerospace and medical device manufacturing.

Read recommendations:

Sealing ring Precision electronic parts

Housing components for recessed downlights Precision electronic parts

Oval Magnetic Hardware Precision electronic parts

CNC Machining Dimension Accuracy

CNC processing factory - Meeting customers' strict requirements for precision