激光热处理对球墨铸铁接触疲劳性能影响的研究

Influence of Laser Heat Treatment on the Contact Fatigue Life of Nodular Cast Iron

本文研究了激光热处理对两种基体组织不同的球墨铸铁接触疲劳性能的影响,结果表明:球墨铸铁经激光热处理后接触疲劳极限可提高300～400N/mm^2;激光硬化层深度对接触疲劳极限有很大影响,硬化层愈深,接触疲劳极限愈高;接触疲劳裂纹大多产生在试样表面硬化区一基体交界处;提高铸铁基体强度,降低硬化区与基体问的强度差有利于提高铸铁所接触疲劳强度。

This paper deals with the influence of laser heat treatment on the microstracture and contact fatigue life of two different matrix nodular cast iron. The results showed that the contact fafigue life of The The two nodular cast irons increased in 300～400 N/mm^2 by laser heat treatment the greater the hardening depth the higher the contact fatigue life. The contact fatigue cracrks are generally initiated at the surface of specimens, at the melting—hardening Zone and the hardening Zonematrix interface. Thus increased of the matrix Strength between the hardening Zone and matrix may beneficially improve the contect fatigue life.