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

【摘要】：隨著國民經(jīng)濟的增長與材料技術的發(fā)展,不銹鋼材料已在機械行業(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)良的機械性能,由不銹鋼材料所制造的零件不僅強度好,使用壽命也較其他材料高。然而其鍛造難度較大,對工藝的把控嚴格,導致了國內(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合有限元分析的方法,對其鍛造工藝參數(shù)進行優(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型熱模擬試驗機在溫度800℃~1100℃、應變速率0.01s-1~5s-1,應變量在50%下進行等溫熱壓縮試驗,得到了11Cr17馬氏體不銹鋼材料的流變應力曲線,并通過擬合推導出了描述該材料熱變形行為的流變應力方程。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構特點設計了適合該產(chǎn)品局部鍛造工藝,并結合有限元分析軟件Forge對鍛造過程進行模擬分析,得到了傳動桿鍛造的成形載荷曲線、模具應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,設計了多目標正交試驗,得到了對模具壽命綜合指標影響程度最大的三個影響因素,通過構建BP神經(jīng)網(wǎng)絡訓練并擬合得到了影響因素與模具壽命指標的非線性函數(shù)映射關系,采用遺傳算法對該映射關系進行尋優(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及優(yōu)化算法相結合,從對材料物理試驗至鍛造過程的有限元分析,再對工藝進行算法尋優(yōu),采用循序漸進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