1. Impact on wear resistance of equipment
(1) Influence of surface roughness on surface wear of parts
Generally speaking, the smaller the surface roughness value, the better the wear resistance. However, if the surface roughness value is too small, the lubricating oil cannot play a role, which will make it easy to bond between the contact surfaces, but increase the wear. Therefore, the roughness on the contact surface needs to have an optimal value, which has a certain relationship with the working condition of the part. When the load is large, the initial wear will also increase, and the optimal value of surface roughness will also increase.
(2) Effect of surface cold work hardening on wear resistance
The cold work hardening of the machined surface will improve the microhardness of the surface layer metal of the friction pair, so it will improve the wear resistance. But this is not absolute. The higher the degree of cold work hardening, the higher the wear resistance will not necessarily be. Because excessive cold work hardening will affect the metal porosity, cracks or metal spalling may occur, which directly reduces the wear resistance.
2. Effect on fatigue strength
(1) Effect of surface roughness on fatigue strength
Under the action of alternating load, fatigue cracks will occur on the surface due to the formation of stress concentration in the concave part of the surface. Therefore, the larger the surface roughness value, the deeper the striation marks on the surface, the smaller the radius of the bottom of the striation, and the ability to resist fatigue damage will become very poor.
(2) Influence of residual stress and cold work hardening on fatigue strength
The residual tensile stress of the surface layer will make the surface appear expanded fatigue cracks and accelerate the fatigue failure; The residual compressive stress of the surface layer can effectively alleviate the fatigue stress and effectively inhibit the occurrence of fatigue failure. Surface cold hardening will be accompanied by the generation of residual compressive stress. Preventing the generation of cracks can also effectively prevent the propagation of existing cracks, which is beneficial to alleviate the fatigue strength.
3. Effect on corrosion resistance
The corrosion resistance of mechanical parts is closely related to the surface quality and surface roughness of parts. The larger the surface roughness value is, the more corrosive objects will be in the depression of the surface, and its corrosion resistance will become worse. The residual tensile stress of the surface layer will cause stress corrosion cracking and reduce the wear resistance of the parts, while the residual compressive stress can prevent stress corrosion cracking.