Effect of Heat Treatment Process on Performance of Disc Spring

Heat treatment processes play a decisive role in determining the performance of disc springs. As a critical core process for enhancing mechanical properties and optimizing microstructure, it directly influences the spring's ultimate elastic performance, fatigue strength, and dimensional stability during long-term use. Given the disc spring's sheet-like geometric structure, it exhibits heightened sensitivity to variations in heat treatment parameters. Consequently, stringent control over these parameters is essential, requiring precise regulation of heating, holding, and cooling stages to ensure optimal results.

1、Key Control Points of Quenching Process

Disc springs are relatively thin, making them prone to issues like uneven heating temperatures and excessive cooling rates during quenching. These factors can cause abnormal grain growth and residual internal stress within the material. Specifically, setting the quenching temperature too high promotes austenite grain growth, resulting in coarse grain structures that significantly increase brittleness and reduce toughness. Conversely, if the temperature is too low, the phase transformation may be incomplete, failing to form sufficient martensite structure post-quenching. This compromises the spring's hardness and strength, falling short of design specifications and leading to suboptimal performance.

2、The Core Function and Parameter Influence of Tempering Process

The primary function of tempering is to eliminate or significantly reduce internal stresses generated after quenching, stabilize the material's microstructural organization, thereby effectively enhancing overall toughness and optimizing elastic properties. Proper setting of tempering process parameters is critical: insufficient tempering temperature fails to adequately relieve internal stresses, leaving residual stresses that may cause deformation or even premature fracture of disc springs during subsequent use; conversely, excessively high tempering temperatures lead to overtempering, resulting in reduced material strength and hardness, material softening, and loss of essential elastic recovery capability in disc springs. Taking commonly used 60Si2Mn spring steel as an example, the standard optimized heat treatment process for manufacturing disc springs typically involves: first quenching at 860–880°C, followed by tempering at 420–450°C. This combined process yields a uniform, fine martensitic structure, endowing disc springs with superior comprehensive mechanical properties.

3、Analysis of Typical Failure Cases Caused by Heat Treatment Defects

In the hydraulic valve system of a construction machinery, the disc spring used previously exhibited excessive residual stress due to improper heat treatment procedures, specifically inadequate tempering. Under prolonged cyclic loading conditions, the residual stress gradually released and redistributed within the spring, triggering elastic relaxation in the material. This compromised its ability to maintain stable pressure regulation, ultimately causing the entire equipment to shut down due to pressure loss and resulting in production disruption. This case clearly demonstrates how heat treatment quality directly impacts the reliability and service life of disc springs.

Quality control and effect verification of heat treatment can typically be conducted through methods such as measuring cross-sectional hardness gradients and observing metallographic microstructures. We are committed to providing professional heat treatment process analysis and optimization solutions. For targeted heat treatment process optimization technical support or more detailed technical consultations, please feel free to contact our relevant business personnel at any time.