本文選題：Ti-6Al-4V合金 + 高速線(xiàn)材軋制　； 參考：《昆明理工大學(xué)》2015年碩士論文

【摘要】：Ti-6A1-4V合金是目前使用最廣泛、最成熟且具有優(yōu)良綜合性能的(α+β)雙相合金。T1-6A1-4V合金小規(guī)格棒線(xiàn)材(Φ5-Φ30mm)被廣泛應(yīng)用于航空航天、海洋、電力、化工、醫(yī)藥衛(wèi)生等眾多領(lǐng)域。目前,Ti-6A1-4V合金小規(guī)格棒材一般采用二輥或三輥軋制、鍛造、拉拔等工藝制備。然而在制備過(guò)程中各道次變形量小,穩(wěn)定性差,棒材尺寸精度低,且生產(chǎn)效率較低。高速線(xiàn)材軋制工藝具有孔型設(shè)計(jì)精確,軋機(jī)的鋼性結(jié)構(gòu)穩(wěn)定,軋制方式高速連續(xù),可用來(lái)軋制Ti-6A1-4V合金棒材,解決上述問(wèn)題。本文采用不同的軋制工藝制備了Φ10mm的Ti-6A1-4V合金小規(guī)格棒材,并進(jìn)行了不同工藝的固溶和時(shí)效熱處理,研究了不同高速線(xiàn)材軋制工藝和熱處理工藝對(duì)合金棒材組織與性能的影響,獲得以下研究結(jié)果：Ti-6A1-4V合金經(jīng)過(guò)高速線(xiàn)材軋制后,合金發(fā)生加工硬化和位錯(cuò)的交互作用,使材料的強(qiáng)度和硬度得到提高。初軋溫度通常選擇在β相變點(diǎn)(960℃)以下進(jìn)行,棒材組織主要為初生等軸α相少量β轉(zhuǎn)變組織,隨溫度升高,棒材組織中等軸α相逐漸減少,β轉(zhuǎn)變組織不斷長(zhǎng)大呈片狀分布,棒材強(qiáng)度和硬度增加,而塑性下降；初軋溫度接近相變點(diǎn)時(shí),組織主要為層片狀β轉(zhuǎn)變組織,棒材的強(qiáng)度和硬度增加,而塑性下降明顯,不能達(dá)到標(biāo)準(zhǔn)要求。將高速線(xiàn)材軋制方法應(yīng)用于制備Ti-6Al-4V合金小規(guī)格棒材,簡(jiǎn)化了生產(chǎn)工藝流程、改善了棒材質(zhì)量的同時(shí)提高了生產(chǎn)效率,為了改善合金的組織與性能,需要對(duì)棒材進(jìn)行不同工藝的熱處理。Ti-6A1-4V合金棒材在退火態(tài)主要由等軸α相和晶間β相組成,溫度為930℃時(shí),分別采用空冷、爐冷、水冷三種冷卻方式進(jìn)行固溶,隨著冷卻速率的加快,等軸α相逐漸消失。爐冷后棒材組織中的a相出現(xiàn)長(zhǎng)大,空冷后棒材的組織中出現(xiàn)少量不穩(wěn)定β轉(zhuǎn)變組織,采用淬火后棒材組織中不穩(wěn)定β轉(zhuǎn)變組織增多且分布均勻。采用水冷固溶后的試樣,分別進(jìn)行不同工藝時(shí)效熱處理。隨著時(shí)效溫度升高,β轉(zhuǎn)變組織分解析出α相,組織主要由(α+β)相和β相混合組成,α相不斷集聚長(zhǎng)大,使組織粗大,棒材抗拉強(qiáng)度降低,延伸率升高。Ti-6A1-4V合金在初軋溫度為900℃時(shí),制備出的Φ10mm的小規(guī)格棒材,經(jīng)(930℃,30min, WQ) + (550℃,4h, AC)熱處理后,棒材強(qiáng)度和塑性達(dá)到最佳配合,抗拉強(qiáng)度為1031MPa,延伸率為12.5%。
[Abstract]:At present, Ti-6A1-4V alloy is the most widely used and mature (偽 尾) dual phase alloy. T1-6A1-4V alloy is widely used in many fields such as aerospace, ocean, electric power, chemical industry, medicine and health, etc. At present, Ti-6A1-4V alloy bars are generally prepared by two or three rollers rolling, forging and drawing. However, in the process of preparation, the deformation of each pass is small, the stability is poor, the precision of bar size is low, and the production efficiency is low. The rolling process of high speed wire rod has the advantages of accurate pass design, stable steel structure of rolling mill and high speed continuous rolling mode. It can be used to rolling Ti-6A1-4V alloy bar and solve the above problems. In this paper, 桅 10mm Ti-6A1-4V alloy bars with small specifications were prepared by different rolling processes, and the effects of different high speed wire rolling and heat treatment processes on the microstructure and properties of the alloy bars were studied. The following results were obtained: after high speed wire rod rolling, the workhardening and dislocation interaction occurred in the alloy Ti-6A1-4V, which improved the strength and hardness of the alloy. The primary rolling temperature is usually below 960 鈩，

本文編號(hào)：1789695