本文選題：鋁熱反應(yīng)　切入點(diǎn)：微納結(jié)構(gòu)　出處：《蘭州理工大學(xué)》2016年博士論文　論文類型：學(xué)位論文

【摘要】：本文通過鋁熱法制備了具有微納結(jié)構(gòu)的304、316L不銹鋼,20、45亞共析碳鋼,其直徑可達(dá)200mm,厚度10mm左右,并研究了不銹鋼退火溫度和時(shí)間、軋制溫度和變形量、先開坯再不同溫度和變形量軋制對(duì)組織的影響;碳鋼退火溫度和時(shí)間、600℃軋制變形量對(duì)組織的影響。通過分析不銹鋼中納米晶奧氏體、亞微米晶奧氏體和鐵素體晶粒尺寸,以及它們的體積分?jǐn)?shù)的變化;亞共析碳鋼中珠光體體積分?jǐn)?shù)、片層間距和滲碳體形狀等,根據(jù)研究結(jié)果提出了微納組織演化機(jī)制。1.對(duì)鋁熱反應(yīng)法制備的微納結(jié)構(gòu)304、316L不銹鋼不同時(shí)間和溫度退火后的組織研究發(fā)現(xiàn),800℃退火后,鐵素體晶粒尺寸隨退火時(shí)間的延長逐漸長大;1000℃退火后,隨退火時(shí)間的延長基本不變,并有Fe Ni Cr Al相析出。納米晶奧氏體晶粒尺寸隨退火溫度的升高或退火時(shí)間的增加不斷增加,體積分?jǐn)?shù)不斷減小,溫度越高或退火時(shí)間越長,這種變化趨勢(shì)越明顯。2.對(duì)304和316L不銹鋼800℃變形量≤60%軋制后,鐵素體晶粒尺寸隨變形量的增加而增大,變形量60%軋制后,隨變形量的增加而減小;304不銹鋼1000℃軋制后,隨變形量的增加基本不變。800℃變形量≤40%軋制后,納米晶奧氏體晶粒尺寸隨變形量的增加而長大,體積分?jǐn)?shù)減少;變形量≥60%軋制后,304不銹鋼中納米晶奧氏體晶粒消失轉(zhuǎn)變?yōu)閬單⒚拙W氏體晶粒,316L不銹鋼中本身的納米晶消失,出現(xiàn)由亞微米晶破碎產(chǎn)生的納米晶。304不銹鋼800和1000℃變形量≤40%軋制后,亞微米晶奧氏體體積分?jǐn)?shù)隨變形量的增加而增加;800℃變形量40%軋制后,隨變形量的增加而減少;1000℃變形量≥60%軋制后,亞微米晶奧氏體晶粒消失。316L不銹鋼800℃不同變形量軋制,隨軋制變形量的增加,亞微米晶奧氏體晶粒尺寸減小,體積分?jǐn)?shù)減少。3.304不銹鋼開坯后700和600℃變形量≤50%軋制后,隨變形量的增加,鐵素體晶粒尺寸增加,變形量為70%軋制后基本不變。隨變形量的增加,納米晶奧氏體晶粒尺寸增加,亞微米晶奧氏體晶粒尺寸減小并分布越來越均勻。700℃軋制后,隨變形量的增加,納米晶和亞微米晶奧氏體體積分?jǐn)?shù)逐漸減少;600℃變形量為50%軋制后,納米晶奧氏體體積分?jǐn)?shù)減小,亞微米晶奧氏體體積分?jǐn)?shù)增加;變形量為70%軋制后,納米晶奧氏體體積分?jǐn)?shù)增加,亞微米晶奧氏體體積分?jǐn)?shù)減小。4.316L不銹鋼開坯后700℃變形量≤50%軋制后,納米晶奧氏體晶粒消失,隨變形量的增加,鐵素體晶粒尺寸和亞微米晶奧氏體體積分?jǐn)?shù)不變;變形量為70%軋制后,亞微米晶奧氏體晶粒破碎產(chǎn)生納米晶奧氏體晶粒,亞微米晶奧氏體體積分?jǐn)?shù)下降,鐵素體晶粒尺寸增加。600℃軋制后,隨變形量的增加,鐵素體晶粒逐漸破碎減小;變形量≥50%軋制后,亞微米晶奧氏體晶粒破碎,有納米晶奧氏體晶粒出現(xiàn),并隨著變形量的增加,亞微米晶和納米晶奧氏體晶粒尺寸減小,納米晶奧氏體體積分?jǐn)?shù)增加,亞微米晶奧氏體體積分?jǐn)?shù)減小。5.20和45鋼經(jīng)600℃退火后,隨退火時(shí)間的延長,珠光體體積分?jǐn)?shù)基本不變,珠光體片層間距逐漸增加。20鋼經(jīng)800℃退火2h后,珠光體基本完全球化;退火16h后,珠光體消失,材料表面析出Fe3C。45鋼經(jīng)600℃退火后,當(dāng)退火時(shí)間≤4h時(shí),珠光體全部為片層狀;當(dāng)退火時(shí)間≥6h時(shí),珠光體開始球化,并且隨著退火時(shí)間的延長,珠光體球化越顯著。45鋼經(jīng)800℃退火2h后,珠光體為層狀,退火16h后,珠光體大部分球化。6.20和45鋼在600℃下不同變形量軋制后,隨變形量的增加,珠光體體積分?jǐn)?shù)基本不變。變形量為20%軋制后,珠光體組織中的滲碳體開始破碎;變形量為40%軋制后,片狀滲碳體破碎為棒狀滲碳體;變形量為60%軋制后,部分棒狀滲碳體破碎為球狀滲碳體;變形量為80%軋制后,滲碳體破碎成亞微米顆粒;變形量為90%軋制后,20鋼組織中的滲碳體繼續(xù)破碎成納米顆粒;而45鋼組織中的球狀滲碳體長大。
[Abstract]:This paper through the aluminum thermal preparation of micro nano structure of 304316L stainless steel with 20,45 hypoeutectoid steel, its diameter is 200mm, thickness of about 10mm, and studied the stainless steel annealing temperature and time, the rolling temperature and deformation, the first blooming again in different temperature and rolling deformation on group effect; annealing temperature and carbon steel time effect of deformation on Microstructure of 600 degrees. Through the analysis of nanocrystalline stainless steel rolling in austenite, sub micron austenite and ferrite grain size, and changes in their volume fraction; pearlite hypoeutectoid carbon in volume fraction, the lamellar spacing and cementite shape, according to the study results of the research organization the micro nano structure of 304316L stainless steel in different temperature and time after annealing in micro nano microstructure evolution mechanism of.1. prepared by aluminothermic reaction, 800 DEG C after annealing, the ferrite grain size increases with the extension of annealing time Grow up; 1000 DEG C after annealing, with prolonging annealing time is basically unchanged, and the Fe Ni Cr Al precipitates. Increasing nanocrystalline austenite grain size with annealing temperature or annealing time increasing, the volume fraction decreases, the higher the temperature or annealing time is longer, the more obvious trend of.2. 304 and 316L 800 stainless steel deformation is less than or equal to 60% DEG C after rolling, ferrite grain size increases with the increase of the amount of deformation and deformation after rolling 60%, decreases with the increase of deformation temperature of 1000 DEG C; 304 stainless steel after rolling, with the increase of deformation of the base deformation is less than or equal to 40% DEG.800 unchanged after rolling nanocrystalline austenite grain size grows up with the increase of deformation, the volume fraction decreased; deformation is more than 60% after rolling, the nanocrystalline austenite grain in 304 stainless steel disappeared into submicron grained austenite grain, nanocrystalline 316L stainless steel in itself Disappeared, nanocrystals of.304 stainless steel produced by sub micron grain crushing 800 and 1000 less than 40% DEG C deformation after rolling, sub micron grained austenite volume fraction increases with the increase of deformation; 800 DEG C after rolling deformation of 40%, and decreased with the increase of deformation; 1000 degrees deformation is more than 60% after rolling submicron grained austenite grains disappeared.316L stainless steel with different deformation temperature of 800 DEG C with rolling, the rolling deformation increases, sub micron grain austenite grain size decreases, the volume fraction of.3.304 is less than 700 and 50% stainless steel rolling deformation of 600 DEG C after blooming, with the increase of deformation, the ferrite grain size increases, deformation 70% after rolling basically unchanged. With the increase of the amount of deformation of the nanocrystalline austenite grain size increases, sub micron grain austenite grain size decreases and the distribution becomes more uniform.700 DEG C after rolling, with the increase of the amount of deformation of nano and submicron crystal The volume fraction of austenite decreases gradually; 600 degrees deformation is 50% after rolling, nanocrystalline austenite volume fraction decreases, submicron crystalline volume fraction of austenite increases; deformation is 70% after rolling, nanocrystalline austenite volume fraction, submicron crystalline volume fraction of austenite decreases after 700.4.316L stainless steel billet deformation is less than or equal to 50% DEG C after rolling, the nanocrystalline austenite grain disappears, along with the increase of deformation, the ferrite grain size and submicron crystalline volume fraction of austenite unchanged; deformation is 70% after rolling, sub micron grain austenite grain crushing of nanocrystalline austenite grains decreased, submicron crystalline volume fraction of austenite, ferrite grain size increased by.600 C after rolling, with the increase of the amount of deformation, the ferrite grain gradually broken decreases; deformation is more than 50% after rolling, sub micron grain austenite grain crushing, nanocrystalline austenite grain, and with the With the increase of deformation, sub micron grained and nanocrystalline austenite grain size decreases, the increase of the volume fraction of nanocrystalline austenite, sub micron austenite volume fraction decreased.5.20 and 45 steel after annealing at 600 DEG C, with the increase of annealing time, the pearlite volume fraction is essentially the same, the interlamellar spacing increased gradually in.20 steel with 800 C after 2H annealing, pearlite spheroidization annealing completely; after 16h, pearlite disappeared, surface precipitation of Fe3C.45 steel after annealing at 600 DEG C, when the annealing time is less than 4h, all of the lamellar pearlite; when the annealing time is greater than or equal to 6h, start pearlite spheroidization, and with the increase of annealing time, the pearlite spheroidization significant.45 steel after annealing at 800 DEG C after 2h, 16h after annealing for lamellar pearlite, pearlite spheroidization, most of.6.20 and 45 steel under 600 degrees different deformation after rolling, with the increase of the amount of deformation of the pearlite volume fraction is essentially the same 20%. The deformation after rolling, cementite in pearlite began breaking; deformation is 40% after rolling, for rod cementite lamellar cementite broken; deformation is 60% after rolling, as part of the rod spheroidite cementite broken; deformation is 80% after rolling, the cementite is broken into sub micron particles; deformation is 90% after rolling, 20 cementite in steel structure to break into nano particles; and 45 spherical cementite in the microstructure of growing up.

【學(xué)位授予單位】：蘭州理工大學(xué)
【學(xué)位級(jí)別】：博士
【學(xué)位授予年份】：2016
【分類號(hào)】：TG156.2;TG335
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本文編號(hào)：1646409