發(fā)布時間：2018-05-08 10:58

  本文選題：11Cr17馬氏體不銹鋼 + 本構(gòu)方程��； 參考：《江蘇大學(xué)》2017年碩士論文

【摘要】：隨著國民經(jīng)濟(jì)的增長與材料技術(shù)的發(fā)展,不銹鋼材料已在機(jī)械行業(yè)內(nèi)得到了廣泛的使用。不銹鋼的顯著特點是其具有較好的抗腐蝕性能及優(yōu)良的機(jī)械性能,由不銹鋼材料所制造的零件不僅強(qiáng)度好,使用壽命也較其他材料高。然而其鍛造難度較大,對工藝的把控嚴(yán)格,導(dǎo)致了國內(nèi)不銹鋼鍛件的生產(chǎn)水平低,產(chǎn)品質(zhì)量不穩(wěn)定。本課題以某鍛造廠生產(chǎn)的11Cr17馬氏體不銹鋼傳動桿鍛件為研究對象,由于11Cr17馬氏體不銹鋼的特殊流變性能,導(dǎo)致了該鍛造模具壽命普遍較低,易產(chǎn)生開裂和磨損等早期失效的情況,為了解決這些問題,提高模具壽命從而降低企業(yè)損失,本文采用物理試驗結(jié)合有限元分析的方法,對其鍛造工藝參數(shù)進(jìn)行優(yōu)化,改善模具失效情況,主要的研究內(nèi)容如下:(1)采用Gleeble-3800型熱模擬試驗機(jī)在溫度800℃~1100℃、應(yīng)變速率0.01s-1~5s-1,應(yīng)變量在50%下進(jìn)行等溫?zé)釅嚎s試驗,得到了11Cr17馬氏體不銹鋼材料的流變應(yīng)力曲線,并通過擬合推導(dǎo)出了描述該材料熱變形行為的流變應(yīng)力方程。根據(jù)動態(tài)材料模型建立了11Cr17不銹鋼的熱加工圖,從而確定11Cr17不銹鋼的最佳熱加工參數(shù)的選擇范圍為溫度900~1050℃、應(yīng)變速率0.05s-1~0.1s-1,并得到了該材料易產(chǎn)生失穩(wěn)缺陷的區(qū)域。(2)根據(jù)渦輪增壓器傳動桿鍛件的結(jié)構(gòu)特點設(shè)計了適合該產(chǎn)品局部鍛造工藝,并結(jié)合有限元分析軟件Forge對鍛造過程進(jìn)行模擬分析,得到了傳動桿鍛造的成形載荷曲線、模具應(yīng)力分布及模具磨損分布情況,與實際生產(chǎn)過程中的模具失效情況相符。(3)為了得到最合理的鍛造工藝參數(shù)組合,設(shè)計了多目標(biāo)正交試驗,得到了對模具壽命綜合指標(biāo)影響程度最大的三個影響因素,通過構(gòu)建BP神經(jīng)網(wǎng)絡(luò)訓(xùn)練并擬合得到了影響因素與模具壽命指標(biāo)的非線性函數(shù)映射關(guān)系,采用遺傳算法對該映射關(guān)系進(jìn)行尋優(yōu),最終得到了11Cr17馬氏體不銹鋼傳動桿件的最優(yōu)鍛造工藝參數(shù)組合。(4)結(jié)合實際生產(chǎn)試驗,證明了由以上方法獲得的最優(yōu)鍛造工藝參數(shù)能夠有效較低模具的早期失效概率,所生產(chǎn)的傳動桿零件成形效果好,尺寸精確無鍛造缺陷。本課題將11Cr17馬氏體不銹鋼的材料特性試驗研究與有限元模擬技術(shù)及優(yōu)化算法相結(jié)合,從對材料物理試驗至鍛造過程的有限元分析,再對工藝進(jìn)行算法尋優(yōu),采用循序漸進(jìn)的研究方法有效改善了模具壽命問題,為今后此種材料及此類產(chǎn)品的實際鍛造生產(chǎn)工藝提供了理論指導(dǎo)及依據(jù)。
[Abstract]:With the growth of national economy and the development of material technology, stainless steel materials have been widely used in machinery industry. The remarkable characteristic of stainless steel is that it has good corrosion resistance and excellent mechanical properties. The parts made of stainless steel not only have better strength but also have higher service life than other materials. However, the forging of stainless steel forgings in China is difficult and strict, which leads to the low production level of stainless steel forgings and unstable product quality. This subject takes the 11Cr17 martensite stainless steel transmission bar forgings produced by a forging factory as the research object. Because of the special rheological properties of the 11Cr17 martensite stainless steel, the forging die life is generally low. In order to solve these problems and increase die life and reduce enterprise losses, this paper optimizes the forging process parameters by means of physical test and finite element analysis. The main contents of the research are as follows: (1) the main research contents are as follows: (1) the Gleeble-3800 thermal simulator is used to carry out the isothermal compression tests at 800 鈩，

本文編號：1861116