本文選題：鐵素體不銹鋼 + 富銅相��； 參考：《北京科技大學(xué)》2016年博士論文

【摘要】：抗菌不銹鋼兼具結(jié)構(gòu)材料和抗菌功能材料的雙重特點,極大地拓寬了抗菌材料的應(yīng)用領(lǐng)域。尤其是低成本的鐵素體抗菌不銹鋼,可廣泛用于家電廚具、衛(wèi)生潔具等金屬抗菌產(chǎn)品。開發(fā)和應(yīng)用具有優(yōu)良抗菌性能的抗菌不銹鋼既可帶來巨大的經(jīng)濟效益,又可產(chǎn)生廣泛的社會價值。本文運用鈮鈦雙穩(wěn)定超純化設(shè)計思路,采用高鉻低鎳設(shè)計思想,添加1.5wt%左右的銅,采用真空感應(yīng)爐冶煉和抗菌處理,成功開發(fā)出抗菌性能、力學(xué)性能、成形性能和耐蝕性能良好配合的超純鐵素體抗菌不銹鋼。通過高溫拉伸試驗研究了加熱溫度和時間、變形溫度和速率對試驗鋼高溫?zé)岽嘈袨榈挠绊憽＝Y(jié)果表明,試驗鋼分別在加熱溫度1150℃、加熱時間60min、變形溫度1150℃和中等變形速率10-2 s-1時,其熱脆敏感性達到最大值。分析認為是銅元素偏聚引起的。通過熱壓縮實驗,獲得試驗鋼的熱變形方程：ε=81×1013sinh(ασ)4.6825 exp(-(323000)/RT)。通過耦合能量耗散圖與流變失穩(wěn)圖,獲得試驗鋼熱加工圖。退火工藝對試驗鋼析出行為具有顯著影響。隨抗菌退火溫度的升高和抗菌退火時間的延長,析出相形狀由球狀向桿狀轉(zhuǎn)變,析出相尺寸和平均間距均增大。富銅相與基體存在K-S關(guān)系,即(111)ε-Cu//(110)α-Fe,[110]ε-Cu//[111]α-Fe。試驗鋼宜采用固溶+抗菌退火的制備工藝�？咕嘶饻囟葹�800℃時,抗菌性能最佳。隨退火時間的延長,抗菌率不斷增加,退火時間為1h后,抗菌率超過99%。析出相數(shù)量和尺寸達到獲得良好抗菌性能的臨界值,分別為(54.1±2.0)nm和173/100μm。銅析出相體積分數(shù)需超過0.77%。析出相尺寸和單位面積內(nèi)析出相數(shù)量也是達到良好抗菌效果的重要因素。通過熱力學(xué)計算軟件Themo-calc模擬試驗鋼沉淀開始析出溫度為926℃；800℃時,銅析出相體積分數(shù)約為0.775%。根據(jù)錯配位錯理論,對銅析出相在試驗鋼基體中沉淀析出過程進行理論計算,得到形核率-溫度曲線(NrT曲線)和相變動力學(xué)曲線(PTT曲線)。對銅析出相Ostwald熟化過程進行了表征。熟化速率為m=((8σVpDCo)/(9CpRT))1/3,800℃時,實測析出相平均顆粒尺寸為rt=2.46t1/3。通過原子探針層析技術(shù)(APT)測試了不同時效時間試驗鋼中富銅相的演化規(guī)律。隨著時效時間的延長,納米富銅相的尺寸逐漸增大,數(shù)量密度降低。長大過程中,Mn和Ni原子在富銅相表面發(fā)生偏聚從宏觀和微觀兩方面探討了析出相的抗菌機理。通過拉伸試驗測定試驗鋼的平均塑性應(yīng)變比rm和各向異性指數(shù)△r,探討其與抗菌退火溫度和時間,以及微觀織構(gòu)的關(guān)系。通過動電位極化曲線測定試驗鋼耐點蝕性能。隨著退火溫度的升高和退火時間的延長,試驗鋼的點蝕電位均下降。富銅相尺寸越大,越不利于材料的耐蝕性能。
[Abstract]:Antibacterial stainless steel has the dual characteristics of structural materials and antibacterial functional materials, which greatly broadens the application field of antibacterial materials. Especially low-cost ferrite antibacterial stainless steel, can be widely used in household appliances kitchen utensils, sanitary ware and other metal antibacterial products. The development and application of antibacterial stainless steel with excellent antibacterial properties not only bring great economic benefits, but also produce a wide range of social values. In this paper, using the design idea of niobium and titanium double stable super-purification, adopting the design idea of high chromium and low nickel, adding about 1.5 wt% copper, using vacuum induction furnace smelting and antibacterial treatment, the antibacterial and mechanical properties have been developed successfully. Ultra-pure ferrite antibacterial stainless steel with good formability and corrosion resistance. The effects of heating temperature, time, deformation temperature and rate on the high temperature embrittlement behavior of the steel were studied by high temperature tensile test. The results show that the thermal embrittlement sensitivity of the test steel reaches the maximum at 1150 鈩，

本文編號：1928791