【摘要】：變形鋁合金在工業(yè)裝備中具有廣泛的應(yīng)用,其中5083鋁合金具有代表性,該系列合金具有優(yōu)良的力學(xué)性能和機(jī)械加工性能,可用作各種成形工藝,廣泛地被車(chē)輛、輪船等交通行業(yè)采用。高鎂鋁合金板材在軋制過(guò)程中的邊緣裂紋問(wèn)題一直是制約板材軋制質(zhì)量的主要問(wèn)題之一。本文采用熱力物理模擬、數(shù)值模擬與軋制實(shí)驗(yàn)結(jié)合的方法,對(duì)高鎂鋁合金中的代表合金5083鋁合金軋制工藝進(jìn)行了研究。利用Gleeble-1500D熱模擬試驗(yàn)機(jī)對(duì)鑄態(tài)5083鋁合金進(jìn)行了250、300、350、400、450℃以及應(yīng)變速率為0.002、0.01、0.1、1、10 s-1條件下的熱壓縮實(shí)驗(yàn),研究了鑄態(tài)5083鋁合金的熱壓縮變形行為,求得本構(gòu)方程(?),構(gòu)建合金加工圖,為制定5083鋁合金軋制工藝參數(shù)提供依據(jù)。拉伸變形試驗(yàn)溫度分別為25℃、100℃、200℃,應(yīng)變速率為0.1 s-1、1 s-1、10 s-1,求得斷裂門(mén)檻值C。利用有限元軟件Deform-3D對(duì)鑄態(tài)5083鋁合金進(jìn)行數(shù)值模擬,預(yù)測(cè)了鋁合金軋制裂紋萌生的條件,并用軋制實(shí)驗(yàn)對(duì)其驗(yàn)證,數(shù)值模擬結(jié)果與軋制實(shí)驗(yàn)結(jié)果誤差小于5%。對(duì)切割好的板材試樣在軋機(jī)上進(jìn)行軋制實(shí)驗(yàn),變量為軋制變形量、軋制道次、退火溫度和合金鎂含量,結(jié)果表明:當(dāng)軋制變形量由49%增大到75%,軋制裂紋長(zhǎng)度由0.12 mm增大到0.95 mm;當(dāng)軋制變形量為80%時(shí),5083鋁合金經(jīng)過(guò)1道次軋制后裂紋萌生長(zhǎng)度為0.97 mm,5道次軋制后裂紋萌生長(zhǎng)度為0.69mm;鋁合金板材經(jīng)過(guò)40%軋制后在150、200、250、300和350℃退火再進(jìn)行40%軋制,在150℃裂紋萌生長(zhǎng)度為1.96 mm,在300℃裂紋萌生長(zhǎng)度為0.4mm,退火溫度達(dá)到300℃后,板材裂紋長(zhǎng)度不在變化;在相同軋制條件下,軋制裂紋隨著合金中鎂含量的提高成指數(shù)增長(zhǎng),在60%變形量時(shí)裂紋長(zhǎng)度隨鎂含量變化方程為y=0.000570x6.57。根據(jù)數(shù)值模擬和軋制實(shí)驗(yàn)確定的參數(shù),對(duì)軋制實(shí)驗(yàn)設(shè)備的參數(shù):摩擦系數(shù)和軋輥直徑大小進(jìn)行了模擬,得到摩擦系數(shù)為0.3、0.4、0.5和輥徑為150 mm、180 mm、240 mm時(shí)板材進(jìn)行軋制實(shí)驗(yàn)的軋制裂紋長(zhǎng)度、有效應(yīng)變、有效應(yīng)變速率及軋制力的變化,結(jié)果表明:在軋制條件一定情況下,當(dāng)摩擦因數(shù)由0.5減小到0.3,裂紋長(zhǎng)度逐漸減小,在摩擦因數(shù)為0.3時(shí)不再產(chǎn)生裂紋;在輥徑為150mm軋制時(shí)裂紋萌生長(zhǎng)度為0.324 mm,在輥徑為240 mm軋制時(shí)裂紋萌生長(zhǎng)度為0,表明增大軋輥直徑可以降低軋件邊部裂紋的萌生。
[Abstract]:The deformed aluminum alloy has a wide range of applications in industrial equipment, among which 5083 aluminum alloy is representative. The alloy has excellent mechanical properties and machinability, and can be used as a variety of forming processes, widely used in vehicles. Steamships, etc., are used in the transportation industry. The edge crack in the rolling process of high magnesium aluminum alloy plate is one of the main problems that restrict the rolling quality of high magnesium aluminum alloy plate. In this paper, the rolling process of representative alloy 5083 aluminum alloy in high magnesium aluminum alloy has been studied by means of thermo-physical simulation, numerical simulation and rolling experiment. The hot compression deformation behavior of as-cast 5083 aluminum alloy was studied by means of Gleeble-1500D thermal simulation machine at 250300350400450 鈩，

本文編號(hào)：2455774