Phase Transformation and Mechanical Properties of Ph Stainless Steel by Different Aging Methods Coupling Subzero Treatment(I)

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簡歷

基本資料

Project title

Code/計畫編號

MOST109-2221-E019-047

Translated Name/計畫中文名

不同時效方法耦合深冷處理對析出硬化不銹鋼的相變態及機械性能探討(I)

Project Coordinator/計畫主持人

Shing-Hoa Wang

Funding Organization/主管機關

National Science and Technology Council

Department/Unit

Department of Mechanical and Mechatronic Engineering

Website

https://www.grb.gov.tw/search/planDetail?id=13534922

Year

2020

Start date/計畫起

01-08-2020

Expected Completion/計畫迄

31-07-2021

Bugetid/研究經費

1576千元

ResearchField/研究領域

材料科技

本研究利用不同於傳統的恆溫時效，改以熱循環時效(thermal cycling aging)及潛變時效(creep aging)，所產生的熱應力及晶格缺陷(例如：原子空缺和插排)，預期有助於微觀組織的相變態及奈米析出物改變。探索不同時效方法，不同時效溫度，及不同時效時間，各參數對含少量delta肥粒鐵的麻田散鐵基地相的變化，雙晶形成，銅析出物的形態及分佈，G-Phase的生成可能性，反向回逆γ(inverted/reverted austenite)相的生成。另時效後經液態N2深冷處理，將反向回逆γ，再變態成麻田散鐵等效應。開發創新結構材料的工業應用，接續實施機械性質的探索，分析上述的各種相變態不同組合，含反向回逆γ相、G-Phase、雙晶、插排形態，銅析出物、反向回逆γ變態麻田散鐵等，是否有益於拉伸強度和衝擊韌性之改善。期盼降低成本下，即不需添加微量特殊合金，透過新製程可創造出高強度、高延性、高韌性結合之新結構材料。本研究將以2年時間完成，第1年：先均質化3天，選擇最佳固溶溫度及固溶時間，分別經水淬、液態N2淬火，及油淬，來控制殘留delta肥粒鐵含量及麻田散鐵的packet尺寸大小。隨後完成各於400C、480C、550C溫度下，不同時間的熱循環時效(thermal cycling aging)及潛變時效(creep aging)，並分析各不參數的各種微觀結構、差排結構、雙晶、奈米析出物及結晶方位關係。第2年：延續第1年研究外，實施各種時效參數的拉伸和衝擊機械性能實驗，包括具反向回逆γ及深冷處理後反向回逆γ變態成麻田散鐵的不同組成相的機械性能實驗。探討各種機械特性呈現與不同微觀組織的密切關聯性。期盼本計畫完成後，將現有的析出硬化型不銹鋼，創新改良成具有優越，強度延性韌性組合的新結構材料，成功應用於石化業及發電廠的關鍵零組件、管件及各類重要的結構件等。 This study uses the thermal cycling aging and creep aging, which are different from the traditional isothermal temperature aging. The thermal stresses and lattice defects (such as vacancies and dislocations) generated are expected to contribute to the phase transformation of microstructure, and the changes in nano-sized precipitates. The different aging methods under different aging temperatures with different aging times will be used to explore the changes of martensitic matrix containing a small amount delta ferrite, the formation of twins, the form and distribution of copper precipitates, and the possibility of G-Phase. In addition, it needs to be understood the formation of inverted/reverted austenite after the aging effect, and the martensitic formation from the inverted/reverted austenite by liquid N2 cryogenic treatment. For the industrial applications of an innovative structural materials, the superior mechanical properties of being beneficial to improving tensile strength and impact toughness are depending on the best combinations of the various phases described above, including G-Phase, twin crystals, dislocation morphology, copper precipitates, inverted/reverted austenite. This project can create a new structural material with high strength, high ductility, and high toughness through these new aging process under low cost without add more alloys. This project will be completed in 2 years. The first year: the optimal solution temperature and solution time will be selected after homogenize for 3 days to control the amount of residual delta ferrite and martensite packet size by water quenching, liquid N2 quenching, and oil quenching, respectively. Then thermal cycling aging and creep aging will be conducted at different temperatures of 400C, 480C, and 550C. The resulting various microstructures and crystal orientation will be analyzed. The second Year: Continuing the first year of research, the tensile and impact experiments of various aging parameters will be carried out, including the existence of inverted/reverted austenite and martensite formation from inverted/reverted austenite after cryogenic treatment. The relationship between various mechanical characteristics and different microstructures will be investigated. It is expected that after the completion of this project, the current precipitation-hardening stainless steel will be innovatively improved into a new structural material with superior strength, ductility and ductility to apply for the main parts, pipes and various important components of the petrochemical industry and power plants.

Keyword(s)

麻田散鐵
G-相
深冷處理
熱循環時效
潛變時效
ε-銅
Martensite
G-phase
Subzero treatment
thermal cycling aging
creep aging
ε-Cu

DSpace CRIS

Phase Transformation and Mechanical Properties of Ph Stainless Steel by Different Aging Methods Coupling Subzero Treatment(I)

基本資料

Description