本文選題：GH4169合金摩擦焊　切入點：微觀組織　出處：《山東大學(xué)》2017年碩士論文　論文類型：學(xué)位論文

【摘要】：GH4169鎳基高溫合金由于其在高溫下具有高強度、塑性、良好的抗氧化性、抗耐熱腐蝕性、斷裂韌性和疲勞性能等優(yōu)點,而被廣泛應(yīng)用于航空發(fā)動機(jī)壓氣機(jī)盤、渦輪盤、機(jī)匣、壓氣機(jī)葉片和緊固件等熱端部件上,而優(yōu)質(zhì)高效的焊接工藝是保證高溫合金材料在航空發(fā)動機(jī)熱端部件能夠滿足精度、性能以及可靠性要求的關(guān)鍵技術(shù)。作為一種優(yōu)質(zhì)高效、環(huán)境友好的固相焊接技術(shù),摩擦焊具有工藝控制參數(shù)少、熱輸入低、變形小、尺寸精度高等獨特優(yōu)勢,尤其適用于高溫材料的焊接,并已經(jīng)成功應(yīng)用于國外多種先進(jìn)商用航空發(fā)動機(jī)熱端部件的制造�；诖�,本文研究了 GH4169鎳基高溫合金軸向摩擦焊接工藝,在試驗范圍內(nèi)獲得最優(yōu)焊接工藝參數(shù):摩擦壓力P1=100MPa、摩擦?xí)r間t1=10 s、轉(zhuǎn)速n=2200 rpm、頂鍛壓力P2=200MPa以及頂鍛時間t2=10s。對最優(yōu)接頭進(jìn)行常溫與高溫(650℃)拉伸性能測試,試驗結(jié)果表明,試樣在常溫拉伸與高溫拉伸條件下均斷裂在母材,常溫拉伸時平均強度為800MPα,延伸率為60%,斷面收縮率為69.75%。高溫拉伸強度為649.6 MPa,延伸率為60%,斷面收縮率為41.2%。對接頭微觀組織分析得出,隨著摩擦壓力的增大,焊接接頭的變形區(qū)從橢圓狀變?yōu)?B"型形貌,最終呈現(xiàn)"啞鈴"狀形貌。而隨著摩擦?xí)r間的增加,試樣的微觀形貌并沒很大的改變。焊接后接頭處存在超細(xì)晶區(qū)、細(xì)晶區(qū)以及熱力影響區(qū),在這些區(qū)域內(nèi)都存在母材原有的(Nb,Ti)(C,N)化合物,超細(xì)晶區(qū)部分(Nb,Ti)(C,N)化合物發(fā)生了破碎、氧化。在焊接過程中,隨著摩擦壓力和摩擦?xí)r間的增加,熱輸入增加,變形區(qū)寬度增加,試樣中心變形區(qū)最后演變?yōu)榧?xì)晶區(qū)和熱力影響區(qū),試樣邊緣變形區(qū)最后演變?yōu)槌?xì)晶區(qū)、細(xì)晶區(qū)和熱力影響區(qū)。隨著摩擦壓力的增加,非界面處的區(qū)域?qū)挾仍黾?晶粒度減小。隨著摩擦?xí)r間的增加,試樣中心各區(qū)域?qū)挾仍黾?晶粒度也增加。而試樣邊緣超細(xì)晶區(qū)寬度減小,細(xì)晶區(qū)寬度先增大后減小,晶粒度減小,熱力影響區(qū)寬度增加,晶粒度減小。當(dāng)熱輸入很大時,焊縫中心處熱力影響區(qū)晶界上形成y/Laves共晶相,分析認(rèn)為GH4169合金摩擦焊接過程中在熱輸入較大的條件下在熱力影響區(qū)發(fā)生了成分液化,通過離異共晶的方式生成y/Laves共晶相。
[Abstract]:Because of its high strength, plasticity, good oxidation resistance, heat resistance, fracture toughness and fatigue properties, GH4169 nickel-base superalloy is widely used in aero-engine compressor disc, turbine disk, casing, etc. In hot end parts such as compressor blades and fasteners, high quality and high efficiency welding technology is the key technology to ensure that superalloy materials can meet the requirements of accuracy, performance and reliability in the hot end parts of aeroengine. Environment friendly solid phase welding technology, friction welding has a few process control parameters, low heat input, small deformation, high dimensional accuracy and other unique advantages, especially suitable for high temperature materials welding, And has been successfully used in the manufacture of hot end parts of many advanced commercial aero engines abroad. Based on this, the axial friction welding process of GH4169 nickel base superalloy is studied in this paper. The optimum welding process parameters are obtained in the range of test: friction pressure P1n 100MPa, friction time T110s, rotational speed N2200rpm, top forging force P2=200MPa and top-forging time t210s.The tensile properties of the optimal joint are tested at room and high temperature (650 鈩，

本文編號：1648026