Hot deformation behavior of GH4945 superalloy using constitutive equation and processing map
Hot deformation behavior of GH4945 superalloy using constitutive equation and processing map
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利用本构方程和加工图研究GH4945高温合金的热变形行为
DOI：
10.1016/s1006-706x(17)30094-8
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发表时间：
2017-06-01
影响因子：
2.5
通讯作者：
Wang, Jue
中科院分区：
文献类型：
--
作者：
Shi, Zhao-xia;An, Xiao-feng;Wang, Jue
采用等温压缩试验研究了GH4945高温合金在应变速率为0.001-10.000 S(-1)、总应变为0.7时的热变形行为。动态再结晶是GH4945高温合金热变形的主要软化机制。建立了本构方程，计算出表观活化能为458。446kJ/mol。真实应变0.2、0.4和0.6的加工图谱基本相似，说明应变对加工图谱的影响不大。变形温度和应变速率对材料的耗能效率和失稳因子有显著影响。在温度1082-1131℃、应变率0.004-0.018 S(-1)的条件下，确定了最佳的热加工条件。11341150℃和0.018-0.213 S(-1)的另一个区域也可以被选为最优的热作业条件。初始晶被动态再结晶的晶界所取代。不安全区位于应变速率大于0.274 S(-1)的区域，主要表现为组织不均匀。不建议在不安全的区域进行热作。
The hot deformation behavior of GH4945 superalloy was investigated by isothermal compression test in the temperature range of 1000-1200 degrees C with strain rates of 0.001-10.000 s(-1) to a total strain of 0.7. Dynamic recrystallization is the primary softening mechanism for GH4945 superalloy during hot deformation. The constitutive equation is established, and the calculated apparent activation energy is 458. 446 kJ/mol. The processing maps at true strains of 0.2, 0.4 and 0.6 are generally similar, demonstrating that strain has little influence on processing map. The power dissipation efficiency and instability factors are remarkably influenced by deformation temperature and strain rate. The optimal hot working conditions are determined in temperature range of 1082-1131 degrees C with strain rates of 0.004-0.018 s(-1). Another domain of 1134-1150 degrees C and 0.018-0.213 s(-1) can also he selected as the optimal hot working conditions. The initial grains are replaced by dynamically recrystallized ones in optimal domains. The unsafe domains locate in the zone with strain rates above 0.274 s(-1), mainly characterized by uneven microstructure. Hot working is not recommended in the unsafe domains.