本文選題：GH4169合金　切入點：微觀組織　出處：《中北大學(xué)》2015年碩士論文　論文類型：學(xué)位論文

【摘要】：GH4169鎳基高溫合金廣泛應(yīng)用于發(fā)動機、渦輪盤等航空發(fā)動機重要高溫部件，它要求在高溫高腐蝕的環(huán)境下工作，但GH4169高溫合金強化相γ"在高溫下極不穩(wěn)定，易轉(zhuǎn)化成脆性相δ相，致使合金的綜合性能降低。基于此，本文主要研究選區(qū)激光熔化GH4169鎳基高溫合金中添加元素Re、W并經(jīng)過熱處理后對合金組織以及合金高溫蠕變性能、高溫耐腐蝕性能進行研究。實驗采用光學(xué)顯微鏡、SEM、XRD等對目前存在爭議的δ相進行分析研究。 首先本文經(jīng)過大量單道燒結(jié)線、燒結(jié)面以及燒結(jié)實體實驗獲得一組最佳工藝參數(shù)，獲得最佳的工藝參數(shù)為：激光電流130A，掃描速度130mm/min，掃描間距0.35mm，脈沖寬度5.5ms，激光頻率12Hz，，鋪粉厚度0.15mm；其次在GH4169合金中分別添加不同含量的Re、 W元素,并混合均勻，利用獲得的最佳工藝參數(shù)燒結(jié)規(guī)格20mm×15mm×3mm的長方體小塊，并對加工成型的試樣進行固溶處理與時效處理，之后再對試樣分別進行高溫蠕變實驗與高溫?zé)岣g實驗。分析元素Re、W對合金蠕變性能及高溫?zé)岣g性能的影響。 實驗結(jié)果表明：1）添加元素Re、W都可以增強GH4169合金的顯微硬度值，且隨著元素Re、W含量的增加而增加；2）將含Re、W和未添加任何元素的GH4169合金進行固溶+時效處理，含Re元素合金的顯微硬度值要高于GH4169合金的顯微硬度值，而GH4169的顯微硬度值要高于添加W元素合金的顯微硬度值；且添加Re元素的合金熱處理后含有較少的δ相，含元素W的合金與未添加任何元素的GH4169合金熱處理后均有δ相和長方形狀的碳化物析出3）添加元素Re的合金其蠕變壽命要高于添加W元素合金的高溫蠕變壽命4）在950℃涂敷75％Na2S04+25％NaCl混合鹽的同等條件下，含元素Re鎳基合金的抗熱腐蝕性能明顯好于含元素W的鎳基高溫合金，未添加任何元素GH4169合金的抗熱腐蝕性略好于添加元素W合金。含Re鎳基合金、含W鎳基合金和未添加任何元素的GH4169合金的熱腐蝕進程按照硫化-氧化機理進行分析，提高合金組織均勻性和添加Re元素有益于提高合金的抗熱腐蝕能力。
[Abstract]:GH4169 nickel base superalloy is widely used in engine, turbine disk and other important high temperature parts of aeroengine. It requires working in high temperature and high corrosion environment, but the strengthening phase 緯 "of GH4169 superalloy is extremely unstable at high temperature and easily converted into brittle phase 未 phase." The comprehensive properties of the alloy are reduced. Based on this, this paper mainly studies the microstructure and creep properties of the alloy after heat treatment by adding the element Rew to the selected laser melting GH4169 nickel-base superalloy. The corrosion resistance at high temperature was studied, and the 未 phase was studied by means of optical microscope (SEM) XRD and so on. First of all, a group of optimum process parameters are obtained through a large number of single-pass sintering lines, sintering surfaces and sintering solid experiments. The optimum technological parameters are as follows: laser current 130A, scanning speed 130mm / min, scanning interval 0.35mm, pulse width 5.5ms, laser frequency 12Hz, coating thickness 0.15mm.After adding different contents of Rew elements into GH4169 alloy and mixing them evenly, the optimum technological parameters are as follows: the laser current is 130A, the scanning speed is 130mm / min, the scanning distance is 0.35mm, the pulse width is 5.5ms. The cuboid block of 20mm 脳 15mm 脳 3mm was sintered with the best process parameters, and the sample was treated by solution treatment and aging treatment. Then the creep test at high temperature and the hot corrosion test at high temperature were carried out to analyze the effect of the element Rew on the creep and hot corrosion properties of the alloy. The experimental results show that the microhardness of GH4169 alloy can be enhanced by adding the element Rew, and the microhardness of the alloy increases with the increase of the content of Rew.) the solution aging treatment of the GH4169 alloy containing and without any elements is carried out. The microhardness value of re containing alloy is higher than that of GH4169 alloy, while the microhardness value of GH4169 alloy is higher than that of W element alloy, and the alloy containing re element contains less 未 phase after heat treatment. After heat treatment, 未 phase and rectangular carbide precipitate from the alloys containing W and GH4169 without any elements.) the creep life of alloys with re is higher than that of alloys with W at high temperature (4). Under the same conditions as the mixed salt of Na _ 2S _ 04 _ 25 and Na _ 2S _ 04 _ 25 coated at 950 鈩

本文編號：1615548