用鋁熱法制備微納結構304和316L不銹鋼。試樣直徑120mm,厚度15mm。試樣不同變形量軋制再退火之后它的組織演變被研究。分析納米晶奧氏體的晶粒尺寸和它的體積分數(shù)。根據(jù)研究結果下列組織演變機制被提出:1.304不銹鋼在1000℃下軋制變形40%之后再在700℃下分別軋制變形40%,60%和80%。當變形量不大于60%時,納米相隨變形量的增加而增加。當軋制變形量達到80%時,納米晶轉變?yōu)閬單⒚准壓臀⒚拙А＼堉谱冃瘟繛?0%,60%和80%時,納米晶的體積分數(shù)分別為21.7%,0.4和8.9%,亞微米晶的體積分數(shù)分別為18.7%,24.7%和32.2%。2.304不銹鋼經(jīng)過1000℃-40%-700℃-40%軋制后,再經(jīng)800℃退火1h和8h結果表明隨著退火時間的延長,絕大部分的納米晶奧氏體消失,微米晶奧氏體體積分數(shù)減小。退火1h和8h后納米晶的體積分數(shù)分別為23.6%、3.1%,亞微米晶的體積分數(shù)分別為27.2%和24.7%。當304不銹鋼經(jīng)過1000℃-40%-700℃-60%軋制后,再在800℃退火1h后,納米晶奧氏體和微米晶奧氏體的體積分數(shù)分別為7.3%和38.6%。3.鋁熱法... 

【文章來源】：蘭州理工大學甘肅省

【文章頁數(shù)】：65 頁

【學位級別】：碩士

【文章目錄】：
摘要
Abstract
Chapter 1 Introduction
    1.1 Bulk nanostructured materials
    1.2 Fabrication of Bulk Nano Crystalline Alloys
        1.2.1 "Bottom-up" Approaches to fabricate bulk nanocrystalline alloy
        1.2.2 "Top-down" Approaches to fabricate bulk nanocrystalline alloy
            1.2.2.1 Cryomilling
            1.2.2.2 Equal-channel angular pressing (ECAP)
        1.2.3 Thermite reaction melting process
    1.3 Deformation mechanisms in bulk nanostructured metals
        1.3.1 Full/partial dislocation emission from grain boundaries
        1.3.2 Deformation twinning
        1.3.3 Grain boundary grain rotation
        1.3.4 Stress-coupled grain boundary migration
    1.4 Microstructure of bulk nanostructured metals
        1.4.1 Dislocation density
        1.4.2 Grain boundary misorientations
    1.5 Characterization of stainless steel
        1.5.1 Transmission electron microscopy (TEM) imaging
        1.5.2 High Resolution Transmission electron microscopy
    1.6 Thesis structure
Chapter 2 Effect of different rolling thickness reduction on Microstructures of Stainless Steel contained of 5%Fe_2O_3 Prepared by Aluminothermic Method
    2.1 Experiment procedure
        2.1.1 Specimen preparation
        2.1.2 Microstructure characterization
    2.2 Experimental Results and Discussion
    2.3 Discussion
    2.4 Summary
Chapter 3 Effect of rolling with different thickness reduction and then followed Annealing with different Time on Microstructures of 304 Stainless Steel Prepared by AluminothermicMethod
    3.1 Experiment procedure
    3.2 Experimental Results
    3.3 Discussion
    3.4 summary
Chapter 4 Effect of different rolling thickness reduction and Annealing Time onMicrostructures of 316L Stainless Steel Prepared by Aluminothermic Method
    4.1 Experiment procedure
    4.2 Experimental Results
    4.3 Discussion
    4.4 Summary
Conclusion
References
Acknowledgements



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