【摘要】：當(dāng)今汽車節(jié)能減排和提高安全性能問題日益突出，強(qiáng)度級(jí)別在1500MPa以上的熱成形用鋼已經(jīng)在減輕車身重量和提高汽車安全性能方面表現(xiàn)出巨大的優(yōu)勢(shì)，其在未來(lái)汽車車身零件中的應(yīng)用潛力也毋庸置疑。為了研究和開發(fā)新一代具有自主知識(shí)產(chǎn)權(quán)的高性能超高強(qiáng)度熱成形用鋼，滿足國(guó)內(nèi)市場(chǎng)的需求，本文設(shè)計(jì)了四種不同碳含量的熱成形用鋼新鋼種，，對(duì)設(shè)計(jì)的熱成形用鋼進(jìn)行基礎(chǔ)性研究工作，為開發(fā)新型具有自主知識(shí)產(chǎn)權(quán)的熱成形用鋼提供必要的基礎(chǔ)數(shù)據(jù)和設(shè)計(jì)原則。 本文采用熱膨脹法和熱分析法對(duì)四種熱成形用鋼實(shí)驗(yàn)鋼連續(xù)冷卻轉(zhuǎn)變規(guī)律進(jìn)行了分析研究，得到了四種實(shí)驗(yàn)鋼的CCT曲線，觀察了不同冷卻速率下轉(zhuǎn)變的微觀組織。研究結(jié)果表明：增加碳含量，能夠有效的提高熱成形用鋼的奧氏體穩(wěn)定性，鐵素體析出溫度、珠光體轉(zhuǎn)變溫度、貝氏體轉(zhuǎn)變溫度和馬氏體轉(zhuǎn)變溫度下降；同時(shí)增加碳含量提高了熱成形用鋼的淬透性，CCT曲線向右下方移動(dòng)。對(duì)于碳含量為0.35%的熱成形用鋼，當(dāng)以20°C/s的冷卻速率冷卻到室溫，就可獲得100%馬氏體組織。此外，碳含量的增加還可以提高熱成形用鋼冷卻轉(zhuǎn)變后組織的顯微硬度。 最后本文研究了四種實(shí)驗(yàn)鋼的力學(xué)性能，研究結(jié)果發(fā)現(xiàn)：碳含量較低的兩種實(shí)驗(yàn)鋼經(jīng)淬火后得到100%馬氏體組織的抗拉強(qiáng)度低于1500MPa；而碳含量較高的兩種實(shí)驗(yàn)鋼100%馬氏體組織的試樣拉伸時(shí)出現(xiàn)脆性斷裂。針對(duì)這兩種碳含量較高的實(shí)驗(yàn)鋼，我們采用馬氏體、貝氏體或馬氏體、貝氏體、少量鐵素體的復(fù)合組織來(lái)代替100%馬氏體組織，從而使得試樣在淬火后擁有高強(qiáng)度和一定的塑性。
[Abstract]:Nowadays, the problems of energy saving and emission reduction and improving safety performance of automobile are becoming more and more prominent. Hot forming steel with strength grade above 1500MPa has shown great advantages in reducing body weight and improving vehicle safety performance. Its application potential in the future car body parts is beyond doubt. In order to study and develop a new generation of high performance ultra-high strength hot forming steels with independent intellectual property rights to meet the needs of the domestic market, four new types of hot forming steels with different carbon content are designed in this paper. The basic research work of hot forming steel is carried out in order to provide the necessary basic data and design principles for the development of new hot forming steel with independent intellectual property rights. In this paper, the continuous cooling transformation of four experimental steels for hot forming was studied by means of thermal expansion method and thermal analysis method. The CCT curves of four experimental steels were obtained, and the microstructure of the transformation at different cooling rates was observed. The results show that the austenite stability, ferrite precipitation temperature, pearlite transformation temperature, bainite transformation temperature and martensite transformation temperature of hot forming steel can be improved effectively by increasing carbon content. At the same time, the hardenability of hot forming steel was improved by increasing carbon content, and the CCT curve moved to the lower right. For hot forming steel with 0.35% carbon content, 100% martensite structure can be obtained when cooling rate is 20 擄C / s to room temperature. In addition, the increase of carbon content can also improve the microstructure microhardness of hot forming steel after cooling transformation. Finally, the mechanical properties of four kinds of experimental steels are studied. The results show that the tensile strength of 100% martensite microstructure of two experimental steels with low carbon content is less than 1500 MPA after quenching. The brittle fracture occurred in the specimens of 100% martensite microstructure of two experimental steels with higher carbon content. For these two kinds of experimental steels with high carbon content, the composite structure of martensite, bainite or martensite, bainite, and a small amount of ferrite is used to replace the 100% martensite structure, which makes the specimen have high strength and certain plasticity after quenching.
【學(xué)位授予單位】：安徽工業(yè)大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2013
【分類號(hào)】：TG142.1

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 王利;汽車用高強(qiáng)度IF薄鋼板[J];寶鋼技術(shù);1997年01期

2 江海濤;唐荻;米振莉;陳雨來(lái);;工藝參數(shù)對(duì)熱沖壓成型鋼組織性能及硼偏聚的影響[J];材料工程;2010年02期

3 林建平;孫國(guó)華;朱巧紅;胡琦;王立影;田浩彬;;超高強(qiáng)度鋼板熱成形板料溫度的解析模型研究[J];鍛壓技術(shù);2009年01期

4 王利;楊雄飛;陸匠心;;汽車輕量化用高強(qiáng)度鋼板的發(fā)展[J];鋼鐵;2006年09期

5 林建平;胡琦;王立影;鮑文華;呂小青;田浩彬;;USIBOR1500超高強(qiáng)度淬火鋼板點(diǎn)焊性能研究[J];中國(guó)工程機(jī)械學(xué)報(bào);2007年03期

6 彭海紅;陳曄;李國(guó)寶;欒玉武;;X60管線鋼再結(jié)晶和過(guò)冷奧氏體連續(xù)冷卻相變行為的研究[J];鋼鐵釩鈦;2006年04期

7 羅志俊;王麗萍;王猛;沈俊昶;蘇航;;板條M/B組織對(duì)低碳馬氏體鋼強(qiáng)韌性的影響[J];材料熱處理學(xué)報(bào);2012年02期

8 莊百亮;單忠德;姜超;;熱沖壓成形工藝技術(shù)及其在車身上的應(yīng)用[J];金屬加工(熱加工);2010年21期

9 王立影;林建平;朱巧紅;田浩彬;胡琦;;熱沖壓成形模具冷卻系統(tǒng)臨界水流速度研究[J];機(jī)械設(shè)計(jì);2008年04期

10 賀連芳;趙國(guó)群;李輝平;相楠;;基于響應(yīng)曲面方法的熱沖壓硼鋼B1500HS淬火工藝參數(shù)優(yōu)化[J];機(jī)械工程學(xué)報(bào);2011年08期

本文編號(hào)：2285509