發(fā)布時(shí)間：2018-05-22 18:05

  本文選題：鋼坯 + 氧化燒損　； 參考：《華北理工大學(xué)》2017年碩士論文

【摘要】：鋼坯在熱成型、尤其加熱工段,由于加熱溫度高、時(shí)間長,氧化是難以避免的問題,而且也是引起鋼材耗損的重要原因。因此,研究鋼坯在高溫下的氧化燒損機(jī)理,探索一條工業(yè)生產(chǎn)中控制鋼坯氧化燒損的有效途徑,對(duì)指導(dǎo)企業(yè)節(jié)能降耗,產(chǎn)品質(zhì)量和生產(chǎn)技術(shù)升級(jí)以及可持續(xù)發(fā)展具有重要意義,對(duì)我國這樣一個(gè)鋼鐵大國,經(jīng)濟(jì)和社會(huì)效益也十分明顯。通過降低加熱爐中的氧分壓的技術(shù)途徑來減少鋼坯的氧化燒損進(jìn)行系統(tǒng)而深入的研究。選取了三種鋼樣,牌號(hào)分別為08Al、SPHD、Q195。氧分壓(Po2)選擇以下三種:4%(模擬工況Po2),21%(空氣中,大于工況Po2)和0.1%(氮?dú)庵?小于工況Po2);氧化溫度模擬軋鋼廠的加熱爐溫度(1150-1250℃)。通過對(duì)鋼坯隨Po2降低的氧化動(dòng)力學(xué)行為研究,并對(duì)氧化層及相關(guān)區(qū)域的化學(xué)和相組成、組織結(jié)構(gòu)以及形貌特征進(jìn)行了詳細(xì)分析,獲得主要結(jié)果如下:不同鋼種在相同Po2下的氧化機(jī)理(氧化動(dòng)力學(xué)、燒損和氧化皮結(jié)構(gòu)等)不同,鋼種成分(尤其含碳量)相差越大,則差異越明顯。三種鋼在高溫下形成的氧化皮以存在大量孔洞和裂紋等缺陷的Fe O層為主體,冷卻過程中向Fe3O4甚至Fe2O3轉(zhuǎn)變。轉(zhuǎn)變速度與冷卻速度成反比,轉(zhuǎn)變程度與鋼種成分有關(guān)。Po2是影響氧化燒損最主要的因素,降低Po2能顯著降低鋼坯氧化燒損。所有鋼種在三個(gè)溫度(1150、1200及1250℃)下都符合氧化動(dòng)力學(xué)隨Po2降低而顯著降低的規(guī)律。1250℃時(shí),Po2從工況4%降到0.1%時(shí),三種鋼的燒損可降低70-95%,換算成鋼坯的氧化燒損值0.5%,完全達(dá)到了合同中降至1%以下的技術(shù)目標(biāo)。1200和1150℃,通過降低Po2使鋼的燒損至少降低了75%以上,換算成得燒損值要小于0.4%,也完全滿足合同目標(biāo)。降低加熱溫度能有效降低鋼坯氧化燒損。在4%O2條件中,溫度從1250℃降低50℃,08Al燒損減少了12%,SPHD和Q195則在20%以上。溫度再降低50℃,08Al的燒損與1250℃相比降低了24%,SPHD減少了30%,Q195則為40%以上。相比之下,降低Po2比降低溫度更有效地減少了鋼坯的氧化燒損。
[Abstract]:Due to the high heating temperature and the long time, the oxidation of steel billet in hot forming, especially in heating section, is an unavoidable problem, and it is also an important cause of steel wastage. Therefore, it is of great significance to study the oxidation burning mechanism of steel billet at high temperature and to explore an effective way to control the oxidation burning loss of steel billet in industrial production. It is of great significance to guide enterprises to save energy and reduce consumption, upgrade product quality, production technology and sustainable development. To our country such a big country of iron and steel, economic and social benefit is also very obvious. By reducing the oxygen partial pressure in the heating furnace to reduce the oxidation loss of steel billet is studied systematically and deeply. Three kinds of steel samples were selected, and their grades were 08AlN SPHD Q195. Three kinds of oxygen partial pressure (Po2) are selected as follows: 1: 4 (in the air, larger than the operating condition Po2) and 0.1 (in nitrogen, less than that in the working condition); the oxidation temperature simulates the furnace temperature of 1150-1250 鈩，

本文編號(hào)：1923095