A kind of preparation method of copper sleeve

Abstract

The invention discloses a preparation method of a copper sleeve, which is characterized in that: the mass percentage of the copper sleeve is composed of Zn: 28.5-33.5%, Si: 0.7-1.3%, Pb≤0.1%, Fe≤0.5%, and the balance It is Cu and unavoidable impurities; the preparation process of the copper sleeve includes: casting → forming → quenching → annealing; when quenching, the transfer time from removing the copper sleeve from the forming equipment to quenching into the water tank is not more than 15s; the annealing The temperature is 250 ℃ ~ 300 ℃, the holding time is 2h ~ 3h, and air cooling after taking out the copper sleeve. In the invention, quenching is carried out after forming, which not only ensures the strength and hardness of the copper sleeve, but also largely removes the residual stress produced by plastic deformation. Annealing after quenching, the annealing temperature is controlled below the recrystallization temperature of the copper sleeve, which avoids the performance degradation of the material due to recrystallization, and further removes the residual stress inside the material.

Description

A kind of preparation method of copper sleeve technical field The present invention relates to a kind of preparation method of copper sleeve. Background technique The copper sleeve is one of the main parts of the engine. The plug pin is a clearance fit, which is used to reduce the surface contact stress of the piston pin hole and the connecting rod, and improve the reliability of the work. Traditional copper sleeve preparation adopts the mode of cold drawing after extrusion to obtain finished product, but in the forming process, the plastic The inhomogeneous deformation and material flow deformation lead to the generation of residual stress. Residual stress will change the performance of copper sleeve , resulting in problems such as deformation and dimensional accuracy changes during processing, and even cracking during use, resulting in As a result, the entire piston-rod mechanism fails. The method for removing residual stress at present mainly contains natural...

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Problems solved by technology

However, the strength and hardness of the copper sleeve tend to decrease after annealing

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