The forging of main and auxiliary connecting rod is an important part in locomotive. The selection of material and the optimization of its performance have a crucial influence on the overall performance and service life of locomotive. This paper will discuss the principle of material selection, common materials and their properties, and analyze how to optimize the properties.
Material selection principle
Strength and toughness: The main and auxiliary connecting rod forgings need to withstand large loads and impact forces, so the material should have high strength and toughness to ensure that it can maintain stability and durability under various working conditions.
Corrosion resistance: The locomotive operating environment is complex, and the connecting rod forging material should have good corrosion resistance to cope with various harsh environmental conditions.
Processing performance: Good processing performance can reduce production costs and improve production efficiency. Materials should be easy to process, weld and heat treat.
Economy: Under the premise of meeting the performance requirements, reasonable prices and resource-rich materials should be selected to reduce production costs.
Common materials and their properties
Cast iron: Cast iron has excellent wear resistance and corrosion resistance, suitable for carrying large impact loads. However, the strength and toughness of cast iron are relatively low, requiring heat treatment and surface strengthening treatment.
Carbon steel: Carbon steel has good strength, toughness and wear resistance, suitable for the manufacture of high requirements of the main and auxiliary connecting rod forgings. Commonly used carbon steel are low carbon steel, medium carbon steel and high carbon steel.
Stainless steel: Stainless steel has excellent corrosion resistance and oxidation resistance, which is suitable for main and auxiliary connecting rod forgings working in corrosive environments. The strength and toughness of stainless steel are also higher, but the price is relatively high.
Performance optimization method
Optimization of material composition: By adjusting the chemical composition of the material, it is possible to improve its mechanical properties and corrosion resistance. For example, the strength and toughness of the material can be improved by adding alloying elements.
Heat treatment: Heat treatment is an important means to improve material properties. By heating, insulation and cooling the material, its internal organizational structure can be changed, so as to achieve the purpose of improving performance. Common heat treatment methods are quenching, tempering, annealing and so on.
Surface strengthening treatment: Surface strengthening treatment can improve the wear resistance, corrosion resistance and fatigue resistance of the material. Common methods include shot peening, carburizing hardening, nitriding and so on.
Process optimization: Reasonable processing technology can reduce material damage and stress concentration, improve the overall performance of connecting rod forgings. For example, the use of finishing and superfinishing processes can improve the surface finish of parts.
Structural design optimization: Reasonable structural design can reduce stress concentration and vibration, improve the stability and durability of connecting rod forgings. For example, optimizing the cross section shape and size of connecting rod forgings, reducing weight and other measures can improve its dynamic performance.
This paper discusses the material selection and performance optimization of main and auxiliary connecting rod forgings, and draws the following conclusions and suggestions:
When selecting materials, factors such as strength, toughness, corrosion resistance, processing performance and economy should be considered comprehensively to select the most suitable materials.
For different working conditions and use of the environment, should choose the appropriate material, such as cast iron for the greater impact load conditions, carbon steel for higher requirements for the occasion, stainless steel for corrosion environment and so on.
By optimizing the chemical composition of the material, adopting reasonable heat treatment and surface strengthening treatment, optimizing the processing technology and structural design, the performance and service life of the main and auxiliary connecting rod forging can be improved.
