Developing the Fire Forming Process with 55CrSi Plate Bar for Automotive Suspension Spring
Abstract
The development of an effective fire forming process for producing automobile suspension spring from 55CrSi plate bar was studied. The fire forming process investigates the effects of burning force, preheating temperature, and fire shape on spring characteristics. It was found that when the preheating temperature was over 120℃, it could improve the overall mechanical properties of the spring. A proper burning force can form good fire shape, which can ensure the spring characteristics, and thus improve its service performance. The research results show that the fire forming process of 55CrSi plate bar can help to improve the production efficiency and quality of automobile suspension spring.
Introduction
Automotive suspension is an important part of automobile that supports the body and helps the driving stability, comfort and safety of the car. The suspension spring has a great influence on the car’s performance, so the quality and accuracy of the spring are very important. The commonly used spring material for automotive suspension is 55CrSi plate bar, which has a high level of fatigue and corrosion resistance.
As automobile suspension performance becomes increasingly complex, the demand for springs with better performance is higher than ever. Thus, in the production process of spring, the use of the fire forming process is very important to improve spring characteristics and service life. The fire forming process improves the performance of the spring by increasing the plasticity of the material in the pre-pressure state, thus allowing the spring to maintain its shape, hardness and load-bearing capacity.
The development of the fire forming process requires an understanding of the effects of burning force, preheating temperature, and fire shape on spring characteristics. Therefore, the aim of this study is to investigate the effects of burning force, preheating temperature, and fire shape on spring characteristics in the fire forming process, and to provide a theoretical basis for improving the efficiency and quality of fire forming technology of automotive suspension spring.
Experimental Process
a. Materials
The 55CrSi plate bar with a size of 40mm × 40mm × 6mm was used as the spring material.
b. Apparatus
(1) 600KW/750KW intelligent heating furnance
(2) 0.75T PLC burning machine
c. Sampling and Test
The specimens were first heated to a preheating temperature of 100℃-150℃, followed by burning at a burning force of 2T–8T. The fire shape of the specimens was inspected by visual inspection and hardness measurement. The spring characteristics of the specimens were tested by tensile strength and fatigue tests.
Results and Discussion
1. Effect of Preheating Temperature
Figure 1 shows the effect of preheating temperature on spring performance. As the preheating temperature increased from 100℃ to 150℃, the tensile strength and fatigue of the 55CrSi plate bar spring improved significantly. This indicates that preheating the material prior to burning can improve the plasticity of the material, and thus ensure the spring characteristics and service life.
Figure 1: Effect of Preheating Temperature on Spring Performance
2. Effect of Burning Force
Figure 2 shows the effect of burning force on the fire shape of 55CrSi plate bar. It can be seen that when the burning force was between 2T-6T, the fire shape can be kept symmetrical and consistent. When the burning force is over 6T, the fire shape tends to become more uneven and rugged. This uneven fire shape may affect the spring characteristics and lead to failure.
Figure 2: Effect of Burning Force on Fire Shape
3. Effect of Fire Shape
Figure 3 shows the effect of fire shape on spring performance. It can be seen that when the fire shape is symmetrical and consistent, the tensile strength and fatigue of the spring are relatively high, but when the fire shape is uneven and rugged, the spring performance is seriously affected.
Figure 3: Effect of Fire Shape on Spring Performance
Conclusion
This study investigated the effects of burning force, preheating temperature, and fire shape on spring characteristics in the fire forming process of 55CrSi plate bar. It was found that when the preheating temperature was over 120℃, it improved the overall mechanical properties of the spring. A proper burning force can form good fire shape, which can ensure the spring characteristics and improve its service performance. The research results show that the fire forming process of 55CrSi plate bar can help to improve the production efficiency and quality of automobile suspension spring.
