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| Effects of aging heat treatment on the microstructure and properties of a new type nickel-based PM superalloy |
| ZHONG Zhi-yong1，2，ZHANG Yi-wen1，2，LIU Jian-tao1，2，JIA Jian1，2，LI Xiao-kun1，2 |
| 1High Temperature Materials Research Institute，China Iron and Steel Research Institute，Beijing 100081， China；2 Beijing Key Laboratory of Advanced High Temperature Materials， Central Iron and Steel Research Institute，Beijing 100081，China |
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Abstract The precipitation phases and microstructure of a new type PM superalloy with aging treatments were observed. The tested mechanical properties were listed as follows ：room temperature，750 ℃ and 815 ℃ tensile， 750 ℃/750 MPa stress rupture，and 815 ℃/450 MPa stress rupture. The effects of different aging treatments on the microstructure and properties of the alloy were analyzed. The results show that high secondary aging temperature leads to Ostwald ripening of γ′ phase，which weakens the strengthening effect of γ′ phase，decreases the room temperature and high temperature strength of the alloy ，and shortens the rupture life obviously. The single stage aging results in no further growth of the secondary γ′ phase，and tertiary γ′ phases doesn′t precipitate. The strength of the alloy increases and the plasticity at high temperature decreases significantly. After HT2 heat treatment，the secondary and tertiary γ′ phase match well，the size of γ' phase is appropriate，the strength is slightly decreased， the plasticity is obviously improved，and the comprehensive mechanical properties are excellent
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Received: 23 January 2019
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2020, Vol. 30 
