Warm forging technology is a kind of metal forming technology which is widely used in manufacturing high strength and high precision forgings. However, in the actual use process, the warm forging forging is often subjected to the action of alternating load, resulting in fatigue failure. Therefore, increasing the fatigue life of warm forging parts has important engineering application value. This paper will introduce some practical methods and practices, in order to provide reference for improving the fatigue life of warm forging parts.
Select high strength, high toughness materials: In order to improve the fatigue life of warm forging forging, high strength and high toughness metal materials should be preferred. For example, alloy steel and titanium alloys have excellent mechanical properties and fatigue resistance, which are suitable for the manufacture of forgings under alternating loads.
Adjust the chemical composition: By adjusting the chemical composition of the material, it can improve its mechanical properties and fatigue resistance. For example, adding an appropriate amount of alloying elements can improve the strength, toughness and corrosion resistance of the material, thereby improving the fatigue life of warm forging forgings.
Optimize the parameters of warm forging process
Control heating temperature: Heating temperature is a key factor affecting the quality and performance of warm forging forging. High heating temperature may lead to grain growth and oxidation, and reduce the mechanical properties of the material. However, too low heating temperature may lead to insufficient plasticity of the material, which is difficult to fill the mold. Therefore, the heating temperature should be precisely controlled to ensure that the material is warm forged in the best plastic state.
Control forging speed and cooling speed: forging speed and cooling speed are also important factors affecting the quality and performance of warm forging forgings. The proper forging speed can ensure that the material is fully filled with the mold to avoid folding, cracks and other defects; The proper cooling rate can refine the grain and improve the mechanical properties and fatigue resistance of the material. Therefore, the forging speed and cooling speed should be reasonably adjusted in the warm forging process according to the nature of the material and the shape of the forging.
Heat treatment and surface strengthening techniques are introduced
Heat treatment: Through the heat treatment process, the internal structure and mechanical properties of warm forging forging can be improved. For example, heat treatment processes such as normalizing, quenching and tempering can refine grains, eliminate residual stress and improve the strength and toughness of the material.
Surface strengthening: Surface strengthening technology is one of the effective means to improve the fatigue life of warm forging parts. For example, shot peening can introduce a compressive stress layer on the forging surface to improve its resistance to alternating loads; Chemical heat treatment such as carburizing and nitriding can form a hardened layer on the surface and improve the wear resistance and fatigue resistance of the surface.
In order to ensure the quality and performance of warm forging parts meet the expected requirements, non-destructive testing and quality control technology should be introduced. For example, non-destructive testing methods such as ultrasonic testing, magnetic particle testing and eddy current testing can be used to detect defects and cracks inside forgings; The quality control methods such as metallographic inspection and mechanical property testing can be used to evaluate whether the microstructure and mechanical properties of the forgings meet the design requirements.
This paper introduces some practical methods and practices, including optimizing material selection and chemical composition, optimizing process parameters of warm forging, introducing heat treatment and surface strengthening technology, and introducing non-destructive testing and quality control technology, so as to provide reference for improving fatigue life of warm forging parts. However, it should be noted that improving fatigue life is a systematic engineering problem that needs to consider multiple factors such as materials, processes, design and use environment. In the future, with the continuous progress of science and technology and the changing market demand, the requirements for warm forging technology and fatigue performance will continue to improve. We should actively explore and practice new processes and materials to contribute to the development of related fields.
