CAJ | 학술논문

通过等温热压缩试验获得Inconel625合金在变形温度为1000～1200℃，应变速率为1～80S^-1条件下的真应力-应变曲线，利用加工硬化率，结合lnθ-ε曲线上的拐点判据及-δ（1nθ）／δε-ε曲线上的最小值，来研究Inconel625合金动态再结晶的临界条件。结果表明，在该实验条件下，Inconel625合金的lnθε曲线均出现拐点特征，对应的-δ（lnθ）／δε-ε曲线出现最小值，该最小值处对应的应变即为临界应变；临界应变随应变速率的增大和变形温度的降低而增加，并且临界应变和峰值应变之间有一定的关系，即εc=0．69εp；动态再结晶时临界应变的预测模型可以表示为εc=4．41×10^-4Z^0.14261。
통과등온열압축시험획득Inconel625합금재변형온도위1000～1200℃，응변속솔위1～80S^-1조건하적진응력-응변곡선，이용가공경화솔，결합lnθ-ε곡선상적괴점판거급-δ（1nθ）／δε-ε곡선상적최소치，래연구Inconel625합금동태재결정적림계조건。결과표명，재해실험조건하，Inconel625합금적lnθε곡선균출현괴점특정，대응적-δ（lnθ）／δε-ε곡선출현최소치，해최소치처대응적응변즉위림계응변；림계응변수응변속솔적증대화변형온도적강저이증가，병차림계응변화봉치응변지간유일정적관계，즉εc=0．69εp；동태재결정시림계응변적예측모형가이표시위εc=4．41×10^-4Z^0.14261。
Hot compression tests of Inconel 625 alloy were conducted at deformation temperature range of 1 000- 200 ℃ and strain rates of 1-80 s^-1 to obtain true stress-true strain curves. The critical conditions of dynamic recrystallization for In- conel 625 alloy were studied by using the work hardening rate θ, combined with the inflection point criterion of in θ-ε curves and the minimum value of -δ（ln θ）/δε-ε curves. The results indicate that the in θ-ε curve of Inconel 625 alloy presents the inflection point, and a minimum value of -δ（In θ）/δε-ε curve appears, which means the critical strain εc. The critical strain increases with the strain rate increasing and the temperature decreasing. And there is a relationship between the critical strain εc and peak strain ε, i. e. εc = 0.69%. The predicting model of critical strain is described as εc = 4.41 × 10^-4 Z^0.142.61