Evaluation of Fatigue Behavior of SAE 9254 Steel Suspension Springs Manufactured by Two Different Processes: Hot and Cold Winding

Abstract

The fatigue resistance is a property that exerts a strong influence on the suspension spring performance in vehicles. The choice of SAE 9254 steel was due to its wide use in the manufacture of these springs and their fatigue properties and toughness. The manufacture of SAE 9254 steel springs has been made by the hot winding process and the heat treatment by conventional quenching and tempering or by cold winding process and induction hardening and tempering. The shot peening induced a compressive residual stress which increased the fatigue life of the SAE 9254 steel. The residual stress profile from the surface of springs showed a peak in the values of the compressive stress for both manufacturing processes. The maximum residual stress in the cold processed spring was higher than the hot processed spring and maintained much higher values along the thickness of the spring from the surface, resulting from manufacturing processes. The fatigue cracking of the springs, without shot peening, started by torsional fatigue process, with typical macroscopic propagation. The fracture surface showed stretch marks with high plastic deformation.

Corrosion behaviour of an industrial shot-peened and coated automotive spring steel AISI 9254

“…However, the presence of retained austenite was not confirmed by optical or SEM examination and XRD was conducted to further verify the bulk material phase which showed fully martensitic phase (Figure 3(a)). These microstructural results are in agreement with those already reported in the literature [7,10,15]. Figure 3(b) presents the Vickers hardness measured across the transverse-cross-sectional sample and the spread in values from the edge to the middle of the sample.…”

“…There have been increasing demands to improve the material performance with the aim to increase the fuel efficiency and reduce CO 2 emission by reducing automotive components' weight. As an attempt to satisfy such demands, the efforts have been focused to improve the spring material's mechanical performance (elasticity, strength, fatigue) by alloying additions and thermo-mechanical treatments [6][7][8][9]15,16]. Coil surface is also shot-peened which generates compressive residual stresses to enhance the fatigue properties and significantly affects the ultimate life of the spring [15,16].…”

“…As an attempt to satisfy such demands, the efforts have been focused to improve the spring material's mechanical performance (elasticity, strength, fatigue) by alloying additions and thermo-mechanical treatments [6][7][8][9]15,16]. Coil surface is also shot-peened which generates compressive residual stresses to enhance the fatigue properties and significantly affects the ultimate life of the spring [15,16]. However, not much work has been reported on corrosion studies of 54SiCr6/SAE9254 coil spring steels.…”

Thermodynamics Analysis of Multiple Microelements’ Coupling Behavior in High Fatigue Resistance 50CrVA Spring Steel with Nanoparticles

“…These cracks will continue to propagate, eventually leading to fatigue failure, which occurs instantaneously without any warning. Thus, fatigue failure of steel springs has a serious impact on mechanical systems [10,11], even causing serious accidents that endanger human life.…”