第四代核能系统换热管用 Inconel 617B的热加工性能与组织特性

Hot processing performance and microstructure of Inconel 617B for heat exchange tube of the fourth generation nuclear power system

利用Gleeble-3500热模拟试验机与Zeiss光学显微镜研究了第四代核能系统换热管用Inconel 617B的热加工性能与组织特性,获取了合金在950~1200℃,0.01~5 s-1变形参数下的真应力-真应变曲线。结果表明,在较低的试验温度下,合金的变形抗力可达到450~550 MPa。此外,构建了合金的功率耗散图、流变失稳图以及热加工图,应变量为0.8时Inconel 617B的功率耗散效率峰值可达到47%,升高变形温度有利于提高合金的热加工性能;危险加工区域集中在较高应变速率(>0.32 s-1)下。结合微观组织分析,合金在温度范围1175~1200℃,应变速率范围0.06~0.5 s-1的加工区间变形可获得均匀的等轴状动态再结晶晶粒,因此,可将该区间确定为Inconel 617B的最佳热加工窗口。

The hot processing performance and microstructure of Inconel 617B used for heat exchange tube of the fourth generation nuclear power system were studied by Gleeble-3500 thermal simulator and Zeiss optical microscope.The true stress-true strain curves of Inconel 617B under deformation parameters of 950~1200℃,0.01~5 s-1 were obtained.The results show that the deformation resistance of the alloy could reach 450~550 MPa at lower test temperature.In addition,the power dissipation maps,instability maps and hot working maps of the alloy were constructed.When the strain was 0.8,the peak power dissipation efficiency of Inconel 617B could reach 47%.Increasing the deformation temperature was conducive to improve the hot working performance of the alloy;the dangerous processing area was concentrated at the higher strain rate(>0.32 s-1).In combination with the microstructure analysis,the uniform dynamic recrystallization grains could be obtained when the alloy was deformed in the temperature range of 1175~1200℃and the strain rate range of 0.06~0.5 s-1,thus the deformation parameters could be determined as the best hot working window of Inconel 617B.