摘要
目的消除典型镍基合金锻件中存在的严重混晶组织,从而提高锻件的力学性能。方法提出“低温δ相时效+高温连续降温退火”双级热处理工艺,研究该热处理工艺对混晶组织演变及高温性能的影响,揭示锻造混晶组织的均匀细化机制。结果利用该工艺可以在提升再结晶形核速率的同时降低再结晶晶粒的生长速率,从而获得平均晶粒尺寸为5.82μm的均匀细小的晶粒组织(达到ASTM12级),并可保证合理的δ相残余含量。同时,晶粒组织的均匀细化使得合金的强度以及塑性等力学性能均较传统DA工艺得到较大的提升,其中650℃屈服强度较DA工艺提升了13.4%。结论连续降温再结晶热处理工艺可以有效改善镍基高温合金锻件中的混晶状态,并显著提升合金的强度和塑性。
Eliminating the deformed mixed and coarse grains in a Ni-based superalloy is necessary to improve the mechani-cal properties.A two-stage annealing treatment including an aging treatment and a subsequent continuous-cooling annealing treatment was proposed.The effects of the proposed two-stage annealing treatment on the microstructures and high-temperature mechanical properties were investigated.Also,the grain refinement mechanism was discussed.The results show that the an-nealing treatment can increase the recrystallization nucleation rate,but reduce the growth rate of recrystallized grains.Thereby,a fine and uniform grain structure with the average grain size of 5.82μm(ASTM12)was obtained.Moreover,the yield strength is increased by 13.4%compared with that of the sample treated by the traditional DA processing.Thus,the proposed two-stage annealing treatment can not only effectively refine deformed grains, but also improve mechanical properties of the hot deformedNi-based alloy.
作者
陈明松
秦刚华
蔺永诚
牟文彪
马艳永
杜晋峰
楼玉民
赵宁宁
CHEN Ming-song;QIN Gang-hua;LIN Yong-cheng;MOU Wen-biao;MA Yan-yong;DU Jin-feng;LOU Yu-min;ZHAO Ning-ning(School of Mechanical and Electrical Engineering,Central South University,Changsha 410083,China;Zhejiang Zheneng Technology Research Institute Co.,Ltd.,Hangzhou 310026,China;Zhejiang Provincial Energy Group Company Ltd,Hangzhou 310007,China;Csec Guohua Electric Power Research Institute Co.,Ltd.,(Beijing),Beijing 100018,China)
出处
《精密成形工程》
北大核心
2021年第3期125-130,共6页
Journal of Netshape Forming Engineering
基金
国家自然科学基金(51775564,51975593)
湖南省科技人才托举工程(2020TJ-Q05)。
关键词
镍基合金
连续降温再结晶
均匀细化机制
力学性能
Ni-based superalloy
continuous-cooling recrystallization annealing treatment
grain refinement mechanism
mechanical properties
