本文選題：奧氏體不銹鋼 + 熱處理��； 參考：《華中科技大學》2015年碩士論文

【摘要】：在當今鋼鐵冶煉生產中,連鑄技術被廣泛地應用并且在不斷地發(fā)展,如何提高連鑄坯的質量是人們越來越關注的問題。為了提高板坯連鑄生產過程中連鑄坯的質量,針對其工作性能的需求,已經研制出了電磁攪拌用的設備——電磁攪拌輥(后文簡稱“電攪輥”),內部未凝固的鋼坯通過電攪輥時,內部的熔體被電磁攪拌力攪動產生對流,從而細化晶粒。但無磁不銹鋼筒體這個電攪輥的關鍵核心部件的材料,依然依賴從國外進口,國內的材料基本無法實現(xiàn)其功能需求。因此,研制能夠滿足實際使用需求的高性能無磁不銹鋼筒體所用材料——無磁奧氏體不銹鋼,對于擺脫對進口材料的依賴、降低生產成本具有非常重要的意義。本文主要對0Cr15Ni25Ti2MoAl VB奧氏體不銹鋼的熱處理工藝進行研究。本文首先對奧氏體不銹鋼的成分、結構進行了介紹,然后闡述了本研究的理論基礎,即各種合金元素在奧氏體不銹鋼組織中的作用機理,合金組織中常見的M23C6、MC等碳化物和金屬間化合物σ相、γ′相的結構及其對材料性能的作用機理,以及相變強化、固溶強化、位錯強化、沉淀強化、細晶強化等奧氏體不銹鋼強化的機理。接著基于所述理論基礎,對0Cr15Ni25Ti2Mo Al VB奧氏體不銹鋼首先進行了退火軟化處理,室溫進爐,隨爐升溫至500℃后保溫4小時,隨后取出空冷,此處理是為了使該材料便于機械加工。然后針對熱處理工藝——固溶時效,設計四因素三水平的正交實驗方案,探究相對最合理的熱處理工藝參數(shù)。對經過不同熱處理工藝方案的試樣,分別從硬度、屈服強度、抗拉強度、斷后伸長率等力學性能數(shù)據(jù)進行分析,得出結果:在固溶處理溫度950℃下保溫5h后油冷,時效處理溫度720℃下保溫14h后空冷的熱處理工藝參數(shù)方案為最佳,材料的硬度達到306HB,屈服強度σs達到839MPa,抗拉強度σb達到1086MPa,斷后伸長率δ為28.1%,材料力學性能優(yōu)異,能夠滿足實際使用的需求。除此之外,用光學、電子顯微鏡對金相組織進行觀察,晶體內大量的析出γ′相[Ni3(Ti,Al)]及各種碳化物,對比各方案的微觀組織結構的差異,并結合各方案的硬度和力學性能進行分析,奧氏體不銹鋼組織中析出γ′相、碳化物等對材料性能的影響十分顯著。
[Abstract]:Nowadays, continuous casting technology is widely used in the production of iron and steel. How to improve the quality of continuous casting billet is more and more concerned. In order to improve the quality of continuous casting billet in the process of slab continuous casting, aiming at the demand of its working performance, An equipment for electromagnetic stirring has been developed-electromagnetic stirring roll (hereinafter referred to as "electric stirring roll"). When the inner unsolidified billet passes through the electric stirring roll, the melt inside is agitated by electromagnetic stirring force to produce convection, thus refining the grain size. However, the non-magnetic stainless steel cylinder, the key core component of the electric stirring roller, still depends on imported materials from abroad, and the domestic materials can hardly meet its functional requirements. Therefore, it is of great significance to develop the non-magnetic austenitic stainless steel, which can meet the practical application requirements, in order to get rid of the dependence on imported materials and reduce the production cost. The heat treatment process of 0Cr15Ni25Ti2MoAl VB austenitic stainless steel was studied in this paper. In this paper, the composition and structure of austenitic stainless steel are introduced at first, and then the theoretical basis of this study, that is, the action mechanism of various alloying elements in the microstructure of austenitic stainless steel, is described. The structure of carbides and intermetallic compounds 蟽 phase, 緯 'phase and their mechanism of action on the properties of materials, as well as phase transformation strengthening, solid solution strengthening, dislocation strengthening, precipitation strengthening, and so on, are common in alloy microstructure. Strengthening mechanism of austenitic stainless steel such as fine grain strengthening. Then, based on the theoretical basis, the 0Cr15Ni25Ti2Mo Al VB austenitic stainless steel was first annealed and softened, entered into the furnace at room temperature, kept for 4 hours after heating up to 500 鈩，

本文編號：1973133