本文關(guān)鍵詞：鑄軋鋁板坯用Cu-0.23Be-0.84Co合金熱變形行為及數(shù)值模擬研究　出處：《河南科技大學(xué)》2015年碩士論文　論文類型：學(xué)位論文

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【摘要】：目前,雙輥連續(xù)鑄軋生產(chǎn)鋁板坯工藝使用的輥套主要為鋼輥套,由于鋼輥套的導(dǎo)熱率較低,導(dǎo)致熔體的凝固速度慢進(jìn)而影響鑄軋速度和產(chǎn)品質(zhì)量。因此,提高鑄軋速度就必須提高熔體的凝固速度,實(shí)現(xiàn)這一目標(biāo)有效的方法是開發(fā)高導(dǎo)熱性輥套材料。鈹銅合金在所有銅合金中,具有高的強(qiáng)度硬度、高的導(dǎo)電導(dǎo)熱性,高的蠕變強(qiáng)度、耐磨耐蝕性、無磁性和沖擊不產(chǎn)生火花等綜合性能,尤其是鈹含量在0.2-0.6wt.%的低鈹高導(dǎo)鈹青銅合金,是提高鋁板坯連續(xù)鑄軋效率和質(zhì)量過程中實(shí)現(xiàn)輥套材料以銅代鋼最具潛力的選材。目前,國內(nèi)外針對鈹銅合金的研究主要集中在鈹含量在1.6-2.0wt.%的高強(qiáng)鈹青銅,而針對某些服役工況以高的導(dǎo)熱/電性能為主的低鈹銅合金(鈹含量0.2-0.6wt.%)的相關(guān)研究和應(yīng)用鮮有報(bào)道。本文以Cu-0.23Be-0.84Co合金為研究對象,研究了該合金的制備工藝以及其熱力學(xué)性能;采用Gleeble-1500熱模擬試驗(yàn)機(jī)對Cu-0.23Be-0.84Co合金進(jìn)行熱壓縮變形試驗(yàn),研究了Cu-0.23Be-0.84Co合金的流變熱變形行為,分析了不同變形條件對合金流變應(yīng)力的影響,計(jì)算了合金的熱變形激活能并建立了Cu-0.23Be-0.84Co合金的熱變形本構(gòu)方程;根據(jù)動態(tài)材料模型加工圖理論構(gòu)建了Cu-0.23Be-0.84Co合金的熱加工圖,揭示了合金熱變形過程中微觀組織變化規(guī)律,獲得了Cu-0.23Be-0.84Co合金最佳熱加工工藝參數(shù),為該合金的實(shí)際熱加工過程提供理論指導(dǎo);借助DEFORM-3D有限元軟件,結(jié)合本文研制的Cu-0.23Be-0.84Co合金材料性能參數(shù),重點(diǎn)分析了鑄軋溫度、鑄軋速度等參數(shù)對Cu-0.23Be-0.84Co合金輥套溫度場及應(yīng)力場分布的影響規(guī)律,并同目前常用的鋼輥套進(jìn)行了對比分析。研究結(jié)果表明:溫度的變化對Cu-0.23Be-0.84Co合金的導(dǎo)熱系數(shù)影響較小,其導(dǎo)熱系數(shù)平均值為239 W/m·K,大約是鋼材導(dǎo)熱系數(shù)的十倍。在熱變形過程中,Cu-0.23Be-0.84Co合金的熱激活能為419.480k J/mol,熱變形時的流變應(yīng)力模型為:65.49 22.25??=e[sinh(0.0041?)]exp(?419480/8.31T)。構(gòu)建的Cu-0.23Be-0.84Co合金熱加工圖表明:當(dāng)變形量為0.1~0.3時,合金熱壓縮變形安全區(qū)較大,主要是中溫高應(yīng)變速率區(qū)和高應(yīng)變速率區(qū);當(dāng)變形量為0.4~0.6時,合金熱壓縮變形主要存在一個安全區(qū),變形溫度450~725℃,應(yīng)變速率為0.7~10s-1區(qū)域。Cu-0.23Be-0.84Co合金輥套數(shù)值模擬結(jié)果表明:在鑄軋過程中,輥套在接觸區(qū)內(nèi)的熱量主要集中在表面層附近,越靠近表面層,溫度越高,而輥套內(nèi)側(cè)溫度變化較小;隨著軋制溫度的升高,銅輥套在鑄軋區(qū)內(nèi)最高溫度越來越高,但最高溫度變化幅度越來越小,當(dāng)鑄軋溫度由650℃升高到700℃時,鑄軋區(qū)內(nèi)輥套最高溫度由328℃升高到365℃,其中在680℃時輥套最高溫度為364℃。當(dāng)鑄軋速度從0.8m/min增加到2m/min時,輥套內(nèi)外表面最大溫差由257℃升高到265℃。表明鑄軋速度對輥套內(nèi)外溫差影響較小;在鑄軋速度為2m/min和鑄軋溫度為680℃條件下,導(dǎo)熱率為239W/m?k的銅輥套表面最高溫度為245℃,而導(dǎo)熱率為25W/m?k的鋼輥套表面溫度為305℃,表明鑄軋輥套表面的溫度場分布受導(dǎo)熱率的影響較大;在鑄軋過程中,Cu-0.23Be-0.84Co合金輥套的壓應(yīng)力主要集中在鑄軋輥套的外表層。
[Abstract]:At present, the use of technology for the production of aluminum slab continuous casting and rolling double roller set mainly for steel roller, steel roller due to the heat conduction rate is low, resulting in the slow solidification rate of the melt and the effects of casting speed and product quality. Therefore, improving the casting speed must improve the solidification rate of the melt, the realization of effective methods the goal is to develop high thermal conductivity material of roll sleeve. Beryllium copper alloy in all copper alloy with high hardness, strength, high conductivity, high creep strength, wear resistance and corrosion resistance, no magnetism and shock does not produce spark comprehensive performance, especially in the low 0.2-0.6wt.% content of beryllium beryllium high conductivity beryllium bronze alloy, continuous casting and rolling material is to improve the efficiency and quality in the process of implementing material roller to copper and steel most potential aluminum slab. At present, the high strength beryllium bronze research for beryllium copper alloy mainly concentrated in beryllium content in 1.6-2.0wt.%, According to the service condition in some low beryllium copper alloy high thermal / electrical properties of (beryllium content 0.2-0.6wt.%) related research and application is rarely reported. Taking Cu-0.23Be-0.84Co alloy as the research object, study the preparation process of the alloy and its thermodynamic performance test; hot compression deformation of Cu-0.23Be-0.84Co alloy using Gleeble-1500 simulated machine hot deformation behavior of Cu-0.23Be-0.84Co alloy was investigated by rheological thermal analysis, the influence of deformation conditions on the stress calculation of alloy alloy rheological, thermal deformation activation energy and the establishment of Cu-0.23Be-0.84Co alloy thermal deformation constitutive equation; processing map according to the dynamic material model theory to construct the processing map of Cu-0.23Be-0.84Co alloy, reveals the change in the process of microstructure deformation of alloy, obtained the best thermal processing of Cu-0.23Be-0.84Co alloy for the parameters. To provide theoretical guidance for actual thermal processing of the alloy; by using DEFORM-3D finite element software, combined with the performance parameters of Cu-0.23Be-0.84Co alloy materials developed in this paper, focus on the analysis of the influence of casting temperature, casting speed distribution parameters such as stress of Cu-0.23Be-0.84Co alloy roller and the temperature field, and with the commonly used steel roll sleeve a comparative analysis. The results show that temperature change has little effect of thermal conductivity of Cu-0.23Be-0.84Co alloy and its thermal conductivity was 239 W/m - K, is about ten times. The thermal conductivity of steel during hot deformation of Cu-0.23Be-0.84Co alloy, the thermal activation energy of 419.480k is J/mol, the thermal deformation of the rheological stress model 65.49: 22.25?? =e[sinh (0.0041?)]exp (? 419480/8.31T). Cu-0.23Be-0.84Co alloy hot processing map construction shows that when the deformation is 0.1~0.3, compression deformation zone alloy The larger, mainly variable rate and high strain rate in high temperature; when the deformation rate is 0.4~0.6, compression deformation of alloy mainly exists a security zone, deformation temperature of 450~725 DEG C, the strain rate of 0.7~10s-1.Cu-0.23Be-0.84Co alloy roller numerical simulation results show that in the process of roll casting, roll sleeve within the contact area of the heat is mainly concentrated in the near surface layer, the more close to the surface layer, the higher the temperature, and the roller inner temperature change less; with the increase of rolling temperature, copper sleeve in cast rolling zone and the highest temperature is higher, but the highest temperature change range is more and more small, when casting temperature. From 650 degrees to 700 degrees, in the cast rolling zone and sets the highest temperature increased from 328 C to 365 C, which is at 680 DEG C and sets a maximum temperature of 364 degrees. When the casting speed increases from 0.8m/min to 2m/min, and set the maximum temperature difference between inner and outer surface of from 257 DEG C to 265. C. Show that the casting speed of roller temperature difference between inside and outside influence small; in casting speed of 2m/min and the casting temperature is 680 DEG C under the condition, the thermal conductivity is 239W/m? The highest temperature of copper roller surface K is 245 DEG C, and the thermal conductivity of 25W/m? K steel roller surface temperature is 305. Show that the casting roller surface temperature distribution by thermal conductivity has great influence; in casting process, Cu-0.23Be-0.84Co alloy roller pressure stress mainly concentrated in the surface layer of cast roll sleeve.

【學(xué)位授予單位】：河南科技大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：TG146.11

【參考文獻(xiàn)】

相關(guān)期刊論文 前1條

1 潘世民;世界鋁連續(xù)鑄軋技術(shù)綜述[J];世界有色金屬;2003年03期

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本文編號：1410043