基于薄片漏斗试样的N06230合金高温低周疲劳性能研究

Study on Low Cycle Fatigue Properties at Elevated Temperature of N06230 Alloy Based on Sheet-Funnel Specimen

设计了薄片漏斗试样和配套弧形薄片夹具,对国产和进口N06230合金管薄片漏斗试样进行650℃高温低周疲劳试验,基于试验数据和能量密度等效方法建立循环应力幅-应变幅关系参数模型,利用有限元方法获得模型常数,并验证模型的准确性;利用该模型获得2种合金管的循环应力幅-应变幅曲线和应变幅-寿命曲线以及Manson-Coffin律参数,并对2种合金管的疲劳性能进行对比。结果表明:根据薄片漏斗试样高温低周疲劳试验数据和确定循环应力幅-应变幅关系参数模型常数,获得的应力幅-应变幅曲线与有限元分析预设的曲线相吻合,拟合优度均高于0.98,说明该模型对于预测材料循环应力幅-应变幅关系具有普适性和精确性;国产N06230合金管的循环应力幅-应变幅曲线及疲劳性能与进口合金管相近。

Sheet-funnel specimens and matched curved sheet fixtures were designed,and low cycle fatigue tests at elevated temperature of 650℃were carried out on domestic and imported N06230 alloy tube sheet-funnel specimens,The cyclic stress amplitude-strain amplitude relation parameter model was established based on test data and energy density equivalent method.The model constants were obtained by finite element method,and the accuracy of the model was verified.The stress amplitude-strain amplitude curves,strain amplitude-life curves and Manson-Coffin law parameters of the two alloy tubes were obtained by the model,and the fatigue properties of the two alloy tubes were compared.The results show that the stress amplitude-strain amplitude curves obtained by the sheet-funnel specimen low cycle fatigue testing data and the determined constants of cycle stress amplitude-strain amplitude relation parameter model was in good agreement with those pre-inputted in finite element analyse,and the fitting goodness was higher than 0.98,indicating that the generalizability and accuracy of the model for predicting the cyclic stress amplitude-strain amplitude relation of materials.The cyclic stress amplitude-strain amplitude curves and fatigue properties of domestic N06230 alloy tubes were close to those of imported tubes.