摘要
研究了微量元素(C,B,Zr)含量、浇注方式和热处理制度对镍基高温合金GMR235组织和性能的影响,并利用热力学软件计算了合金平衡相图。结果表明:设计合金中主要的平衡相为γ′相、M6C碳化物、一次碳化物MC相、M3B2硼化物、M23C6和γ相基体。C含量为0.18%(质量分数)时铸态合金具有较好的持久性能和高温拉伸性能。添加合金元素B、Zr可明显提高合金的持久寿命、改善持久塑性,抑制碳化物析出,并使碳化物颗粒细化。铸模温度为800℃、出钢温度为1420℃时,合金的综合性能最优。经过5h时效后,合金高温持久寿命明显升高且保持了铸态时的塑性。随着时效时间延长,γ′相粗化使合金高温抗拉伸强度降低。
The effect of the micro-alloying elements（C,B,Zr）,casting system and aging treatment on microstructure and mechanical properties of Ni based superalloy GMR235 was studied.The equilibrium phase diagram of the alloy was calculated by Thermo-Calc software.The results show that equilibrium phases contain γ,γ＇,M6C,MC,M23C6 carbides and M3B2.Proper carbon addition can improve the rupture life of the alloy,keep its plasticity and increase the high temperature tensile properties.The addition of micro-alloying elements B and Zr can improve the high temperature stress rupture properties and plastic properties of the alloy,restraining the precipitation of the carbide and refining carbide particles.The optimum properties can be obtained when the mould temperature is 800 oC and tapping temperature is 1420 oC.Rupture life is significantly increased after 5 h aging with good plastic properties like as-cast alloys.？？ coarsens as the aging time gets longer,decreasing the strength of the alloy at high temperature.
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2011年第11期2038-2042,共5页
Rare Metal Materials and Engineering
