STUDY ON REJUVENATION HEAT TREATMENT OF A DIRECTIONALLY-SOLIDIFIED SUPERALLOYDZ125 DAMAGED BY CREEP

The degradation of microstructure and property in turbine blades of aircraft engines is inevitable during their service. Usually, rejuvenation heat treatment is applied to regenerate the original microstructure for extending the service life of blades and improve economic returns. To date, systematic investigations about rejuvenation heat treatment of the directionally-solidified superalloys are limited. In this work, the effect of rejuvenation heat treatment on the degraded microstructure and property of DZ125 superalloy damaged by creep was investigated. The interrupted creep test was first conducted on DZ125 superalloy to simulate the damage of turbine blades during their service. Three rejuvenation heat treatments with the solution temperature at 1230, 1240 and 1250 °C were applied to the interrupted creep specimen. Then, the rejuvenated specimens were retested, and their microstructures as well as creep properties were compared with those of the initial interrupted creep tests. The results showed that no recrystallization occurred after the interrupted creep tests at 1.0% and 3.5% strain followed by *国家高技术研究发展计划项目2012AA03A513和教育部技术支撑重点项目625010337资助 收到初稿日期: 2015-09-26,收到修改稿日期: 2016-01-07 作者简介:张 京,男, 1990年生,硕士 DOI: 10.11900/0412.1961.2015.00505