Passing rate related strain induced metal high-cycle fatigue strengthening method

Abstract

The invention provides a passing rate related strain induced metal high-cycle fatigue strengthening method. The metal is suitable for most metals and components thereof. A proper strain rate is determined through a simple sample tensile test method, metal pre-strain treatment is carried out through the strain rate, and the strengthening effect of one-time pre-strain or multi-time cyclic pre-straincan be achieved. Compared with the prior art, the method is high in applicability, suitable for metal products or components made of different materials and of different structures and suitable for different service environments of metal. According to the method, the mechanism of the strain rate in the aspect of the strain strengthening effect is emphatically explored, the strengthening mechanismis mainly used for improving the plane slippage capacity of dislocation in metal grains and the uniform deformation capacity of crystal lattices, and the generation of a fatigue source is delayed; and a complete, closed and independent dislocation structure is formed at a grain boundary and a phase interface, so that the expansion of fatigue cracks is further hindered. On the basis that existingmechanical equipment is not changed, the high-cycle fatigue performance of metal materials and components can be improved, application and popularization are quite convenient, and good plasticity of target metal can still be kept while the fatigue performance is remarkably improved.

Description

technical field [0001] The invention relates to a physical means of passing rate-related strain, a method for improving the high-cycle fatigue performance of metal materials and structures, and belongs to the technical fields of materials and machinery. [0002] technical background [0003] Many metal components in modern engineering work under cyclic loads, such as crankshafts, connecting rods, rotors, blades, bridges, axles, nuclear reactors, and power generation equipment. Different from low-cycle fatigue, the maximum cyclic stress of high-cycle fatigue is low. Due to the yield strength of metals, high-cycle fatigue fractures usually occur suddenly, and no matter whether brittle or ductile materials, no obvious macroscopic plastic deformation occurs, so it often leads to catastrophic consequences. Many research results have shown that metals in 10 7 Fracture may still occur in the high-cycle fatigue stage of more than one cycle. How to improve the high cycle fatigue per...

AI Technical Summary

Problems solved by technology

There are many patents on different forms of strain strengthening, but there is a lack of research and introduction on the effect of strain rate on strain strengthening

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