本文關(guān)鍵詞：Havnes282耐熱合金組織與性能研究　出處：《昆明理工大學(xué)》2015年碩士論文　論文類(lèi)型：學(xué)位論文

  更多相關(guān)文章： Haynes282合金 長(zhǎng)期時(shí)效 組織演變 力學(xué)性能 持久強(qiáng)度

【摘要】：Haynes282合金是時(shí)效強(qiáng)化型鎳基高溫合金,由于蠕變強(qiáng)度高、高溫組織穩(wěn)定性好以及較好的熱加工性能,而被選作700℃先進(jìn)超超臨界火電機(jī)組汽輪機(jī)轉(zhuǎn)子候選材料之一。汽輪機(jī)轉(zhuǎn)子材料要求在700℃下具有較高的高溫強(qiáng)度、組織穩(wěn)定性、抗氧化性和焊接性等,為保證Haynes282合金在700℃蒸汽參數(shù)下的使用壽命,研究其在700℃甚至更高溫度下長(zhǎng)期時(shí)效及不同應(yīng)力持久過(guò)程中的組織演變和力學(xué)性能變化就顯得尤為重要。實(shí)驗(yàn)研究了固溶處理、700℃和750℃長(zhǎng)期時(shí)效以及700℃持久過(guò)程中的組織變化規(guī)律,并測(cè)試了合金室溫沖擊、拉伸和700℃高溫拉伸等力學(xué)性能,探討了組織變化對(duì)力學(xué)性能的影響。H282合金熱處理為固溶+二次時(shí)效處理,固溶溫度對(duì)合金的最終性能影響較大。因此文中主要對(duì)合金的固溶處理工藝進(jìn)行實(shí)驗(yàn)選擇。隨著固溶溫度的升高,H282合金中未溶碳化物含量、尺寸均減小,力學(xué)性能逐漸降低。最終確定H282合金的最佳熱處理制度為1120℃/2h/AC+1010℃/2h/AC+788℃/8h/AC。H282合金700℃、750℃時(shí)效態(tài)主要析出相為M23C6相、MC相、γ'相。M23C6相富Cr、Mo元素,主要沿晶界分布,少量分布在晶內(nèi)及孿晶端。隨時(shí)效時(shí)間的延長(zhǎng),M23C6相含量逐漸增加,晶界M23C6相粗化長(zhǎng)大呈連續(xù)的鏈狀,且750℃變化較快。MC相主要分布在晶內(nèi),為富Ti、Mo的一次相,呈塊狀,尺寸較大。700℃長(zhǎng)期時(shí)效過(guò)程中,組成元素變化較小,750℃時(shí)效時(shí)形態(tài)和成分有所變化。丫'相是合金的主要強(qiáng)化相,含量較高,主要成分為Ni、Al、Ti,750℃5000h時(shí)析出量約為18.9%。γ'相的粗化長(zhǎng)大規(guī)律符合Ostwald熟化機(jī)制,根據(jù)γ'相顆粒尺寸得到其在700℃、750℃的動(dòng)力學(xué)長(zhǎng)大方程。表明700℃時(shí)效時(shí),γ'相長(zhǎng)大緩慢,時(shí)效溫度升高,長(zhǎng)大速率加快。700℃、750℃時(shí)效過(guò)程中,合金力學(xué)性能變化趨勢(shì)相同。時(shí)效后,沖擊功迅速下降,硬度迅速升高。隨時(shí)效時(shí)間的延長(zhǎng),沖擊功和硬度變化趨于穩(wěn)定。這是因?yàn)?時(shí)效后晶界碳化物連續(xù)分布,成為裂紋形成和擴(kuò)展的通道,弱化晶界,造成沖擊功下降,同時(shí)γ'相的析出強(qiáng)化作用明顯,硬度迅速上升,時(shí)效時(shí)間延長(zhǎng),丫'相粗化長(zhǎng)大,強(qiáng)化作用降低,硬度增加趨勢(shì)變緩。持久強(qiáng)度是衡量H282合金能否作為700℃先進(jìn)超超臨界火電機(jī)組汽輪機(jī)轉(zhuǎn)子材料的重要標(biāo)準(zhǔn),因此對(duì)合金進(jìn)行700℃持久實(shí)驗(yàn)。實(shí)驗(yàn)結(jié)果表明H282合金持久強(qiáng)度較高,700℃10萬(wàn)小時(shí)外推強(qiáng)度大于100MPa,滿(mǎn)足合金設(shè)計(jì)要求。微觀(guān)組織分析發(fā)現(xiàn)應(yīng)力的施加對(duì)γ'相形貌、分布無(wú)較大影響,對(duì)M23C6相形貌有一定影響。持久過(guò)程中裂紋主要在晶界形核產(chǎn)生,并沿著晶界碳化物擴(kuò)展,造成合金斷裂失效。
[Abstract]:Haynes282 alloy is aging strengthened nickel based superalloy, due to creep of high strength, high temperature stability and good heat organization, good processing performance, and was selected as the 700 C Advanced ultra supercritical thermal power unit steam turbine rotor of steam turbine rotor material. The material requirements of high strength, high at 700 DEG C tissue stability, oxidation resistance and weldability, in order to ensure the service life of Haynes282 alloy at 700 DEG C steam parameters, on the 700 C or higher temperature under different stress and long-term aging microstructure evolution and mechanical properties in the process of lasting energy change is particularly important. Experimental study on the solid solution treatment, microstructure evolution and 700 C 750 C and 700 C long term aging process, and test the impact and tensile alloy at room temperature, 700 degrees high temperature tensile mechanical properties, discusses the impact of organizational change on the mechanical properties. Heat treatment for H282 alloy solid solution + two aging treatment, solid solution temperature on the final properties of alloy influence. Therefore this paper focuses on the alloy process experiment. With the increase of the solution temperature of undissolved carbide content in H282 alloy, the size decreased, the mechanical properties decreased gradually. Finally the optimum heat treatment system of H282 alloy is 1120 DEG /2h/AC+1010 DEG /2h/AC+788 DEG /8h/AC.H282 alloy 700 DEG, 750 DEG C aging precipitates of M23C6 main phase, MC phase,.M23C6 phase gamma 'rich Cr, Mo elements, mainly distributed along the grain boundaries, a small amount of the distribution in the grain and twin side. As the aging time prolonged the content of M23C6 phase increases gradually, the grain boundary of M23C6 phase coarsening in a continuous chain, and 750 C.MC rapid change is mainly in the grain, is rich in Ti, Mo a, a massive, large size.700 C long-term aging process, elements of change Small changes in morphology and composition of 750 ageing. Y 'phase alloy is the main strengthening phase, higher content of major components of Ni, Al, Ti, 5000h 750 degrees when the precipitation amount is about the coarsening phase of 18.9%. gamma' growth Ostwald mechanism, according to the size of the particles' gamma at 700 degrees, 750 degrees dynamic growth equation. That 700 ageing, y 'growth is slow, aging temperature increasing, the growth rate accelerated.700 C, 750 C in the aging process, changes in mechanical properties of the alloy after aging. The same trend, the impact energy decreased rapidly, the hardness increases rapidly. With the prolonging of aging time. The impact of changes in the work and the hardness tends to be stable. This is because the aging of grain boundary carbide continuous distribution channels become, crack formation and expansion of the weakening of grain boundaries, the impact of power down, while gamma' phase precipitation strengthening effect is obvious, the hardness of the rapid rise in the aging time, ah. Coarsening, strengthening effect decreased, hardness increased gradually slows down. Lasting strength is a measure of H282 alloy can be used as 700 C Advanced ultra supercritical thermal power unit steam turbine rotor material standard, so the 700 C lasting experiment was carried out on the alloy. The experimental results show that the H282 alloy with high strength and lasting 100 thousand hours, 700 C extrapolation strength greater than 100MPa, to meet the design requirements. The alloy microstructure analysis found that applied to gamma 'morphology stress, influence the distribution, has a certain effect on the M23C6 morphology. In the process of persistent crack mainly in grain boundary nucleation, and along the grain boundary carbide expansion caused by alloy fracture failure.

【學(xué)位授予單位】：昆明理工大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類(lèi)號(hào)】：TG132.3

【引證文獻(xiàn)】

相關(guān)會(huì)議論文 前3條

1 梁永純;袁超;郭建亭;侯介山;;長(zhǎng)期時(shí)效對(duì)GH4698合金組織和性能的影響[A];動(dòng)力與能源用高溫結(jié)構(gòu)材料——第十一屆中國(guó)高溫合金年會(huì)論文集[C];2007年

2 劉正東;;中國(guó)700℃燃煤發(fā)電機(jī)組耐熱材料研發(fā)[A];2011年全國(guó)高品質(zhì)特殊鋼生產(chǎn)技術(shù)研討會(huì)文集[C];2011年

3 彭建強(qiáng);孫福民;王梅英;;700℃以上等級(jí)超超臨界汽輪機(jī)高中壓轉(zhuǎn)子用材探討[A];超超臨界機(jī)組技術(shù)交流2012年會(huì)論文集[C];2012年

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本文編號(hào)：1414819