本文選題：非線性超聲 + 汽輪機(jī)耐熱材料�。� 參考：《華東理工大學(xué)》2015年碩士論文

【摘要】：超超臨界汽輪機(jī)高溫部件長期服役會產(chǎn)生蠕變損傷,對設(shè)備的安全運(yùn)行存在潛在的威脅,快速、有效地檢出高溫構(gòu)件蠕變損傷狀況對保證設(shè)備服役安全意義重大。最近研究表明,材料損傷程度與超聲波非線性效應(yīng)有緊密的聯(lián)受,受到學(xué)者們的廣泛關(guān)注。本文利用實(shí)驗(yàn)室模擬獲得汽輪機(jī)螺栓、轉(zhuǎn)子試樣的不同蠕變損傷水平,進(jìn)行了非線性超聲縱波表征耐熱材料蠕變損傷狀態(tài)的實(shí)驗(yàn)研究,主要研究內(nèi)容和結(jié)果如下：(1)汽輪機(jī)鎳基高溫螺栓材料In783蠕變損傷狀態(tài)的非線性超聲縱波表征實(shí)驗(yàn)研究。以包含不同蠕變損傷水平的高溫鎳基螺栓材料In783為對象,進(jìn)行蠕變損傷水平的非線性超聲縱波表征實(shí)驗(yàn),完成了不同損傷試樣的微觀組織和機(jī)理分析。結(jié)果發(fā)現(xiàn)：超聲縱波非線性參量隨蠕變變形的增大而單調(diào)增加,顯微硬度隨蠕變應(yīng)變的變化與超聲非線性變化趨勢一致,表明超聲縱波非線性參量與材料力學(xué)性能退化存在函數(shù)關(guān)聯(lián)。超聲非線性參量的增大主要源于材料內(nèi)部位錯(cuò)密度的增加及析出相長大�；谖诲e(cuò)-析出相模型預(yù)測得到了與實(shí)驗(yàn)測量值較一致的結(jié)果,表明位錯(cuò)-析出相模型可較好描述鎳基高溫合金與超聲非線性參量的關(guān)系。(2)汽輪機(jī)轉(zhuǎn)子鐵素體耐熱鋼FB2蠕變損傷狀態(tài)的非線性超聲縱波表征實(shí)驗(yàn)研究。進(jìn)行了包含不同蠕變損傷水平的鐵素體鋼FB2的非線性超聲縱波表征實(shí)驗(yàn),完成了不同損傷試樣的微觀組織和機(jī)理分析。結(jié)果發(fā)現(xiàn)：超聲縱波非線性參量隨汽輪機(jī)轉(zhuǎn)子鋼蠕變變形的增大而單調(diào)增加,且超聲非線性參量變化與蠕變損傷機(jī)制存在函數(shù)關(guān)系。進(jìn)一步,以位錯(cuò)密度為中間量,建立了穩(wěn)態(tài)蠕變變形速率與超聲非線性參量的函數(shù)關(guān)系。
[Abstract]:The long-term service of the ultra-supercritical steam turbine high temperature components will cause creep damage, which has a potential threat to the safe operation of the equipment. It is of great significance to detect the creep damage condition of the high temperature components quickly and effectively to ensure the safety of the equipment service. Recent studies have shown that the damage degree of materials is closely related to the nonlinear effect of ultrasonic wave, which has attracted extensive attention of scholars. In this paper, different creep damage levels of turbine bolts and rotor specimens are obtained by laboratory simulation, and the experimental study of nonlinear ultrasonic longitudinal wave characterizing creep damage state of heat-resistant materials is carried out. The main contents and results are as follows: (1) the experimental study of nonlinear ultrasonic longitudinal wave characterization of In783 creep damage of nickel based high temperature bolt material for steam turbine. The nonlinear ultrasonic longitudinal wave characterizing the creep damage level of high temperature nickel-base bolt material In783 with different creep damage levels was carried out. The microstructure and mechanism of different damage samples were analyzed. The results show that the nonlinear parameters of ultrasonic longitudinal wave increase monotonously with the increase of creep deformation, and the variation of microhardness with creep strain is consistent with that of ultrasonic nonlinearity. It is shown that there is a functional correlation between the nonlinear parameters of ultrasonic longitudinal wave and the degradation of mechanical properties of materials. The increase of ultrasonic nonlinear parameters is mainly due to the increase of dislocation density and the growth of precipitated phase. Based on the dislocation-precipitation model, the predicted results are in good agreement with the experimental results. It is shown that the dislocation precipitation phase model can better describe the relationship between nickel base superalloy and ultrasonic nonlinear parameters. The experimental study of nonlinear ultrasonic longitudinal wave characterization of FB2 creep damage state of ferrite heat-resistant steel in steam turbine rotor is presented. The nonlinear ultrasonic longitudinal wave characterization experiments of ferrite steel FB2 with different creep damage levels were carried out. The microstructure and mechanism of different damage samples were analyzed. The results show that the ultrasonic longitudinal wave nonlinear parameters increase monotonously with the increase of creep deformation of turbine rotor steel, and there is a functional relationship between the variation of ultrasonic nonlinear parameters and the creep damage mechanism. Furthermore, the functional relationship between steady state creep deformation rate and ultrasonic nonlinear parameters is established with dislocation density as the intermediate value.
【學(xué)位授予單位】：華東理工大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：TB34

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本文編號：1885416