本文關(guān)鍵詞： 高強(qiáng)鋼 輥壓成形 局部感應(yīng)加熱 成形特性　出處：《北京科技大學(xué)》2017年博士論文　論文類(lèi)型：學(xué)位論文

【摘要】：隨著全球的能源危機(jī)、嚴(yán)峻的環(huán)境壓力以及工業(yè)用鋼結(jié)構(gòu)安全性能設(shè)計(jì)的提高,開(kāi)發(fā)和應(yīng)用先進(jìn)高強(qiáng)鋼是當(dāng)今鋼鐵行業(yè)的改革趨勢(shì),也是汽車(chē)工業(yè)和橋梁工程領(lǐng)域共同關(guān)注的主題。開(kāi)發(fā)先進(jìn)高強(qiáng)鋼及其在結(jié)構(gòu)輕量化中的應(yīng)用,正符合當(dāng)代經(jīng)濟(jì)社會(huì)低碳、節(jié)能、安全、可持續(xù)發(fā)展的理念。而實(shí)現(xiàn)這該理念的三大關(guān)鍵技術(shù)是:高強(qiáng)鋼種類(lèi)的開(kāi)發(fā)和應(yīng)用、結(jié)構(gòu)輕量化設(shè)計(jì)及優(yōu)化和新型制造及成形工藝技術(shù)的創(chuàng)新。盡管高強(qiáng)鋼的諸多優(yōu)點(diǎn)在汽車(chē)工業(yè)和橋梁工程領(lǐng)域備受人們的青睞,但是高強(qiáng)鋼不同于傳統(tǒng)普碳鋼,高強(qiáng)鋼室溫下強(qiáng)度高、成形困難、成形過(guò)程中力學(xué)行為和微觀組織變化更加復(fù)雜,對(duì)成形設(shè)備及工藝提出了更高的要求,所以采用傳統(tǒng)工藝制備高強(qiáng)鋼輥壓件難度很大或根本無(wú)法完成。為解決高強(qiáng)鋼引入傳統(tǒng)輥壓工藝所帶來(lái)的難題,本文提出了高強(qiáng)鋼局部感應(yīng)加熱輥壓成形技術(shù)。即在傳統(tǒng)輥壓變形前,對(duì)其塑性形變區(qū)感應(yīng)加熱到特定的溫度,降低其成形抗力,提高其成形性能,保證變形后工件強(qiáng)度沒(méi)有損失以及變形區(qū)無(wú)明顯的硬化效應(yīng),從而克服高強(qiáng)鋼引入輥壓工藝所面臨的難題。本文從感應(yīng)加熱基礎(chǔ)理論、輥壓成形機(jī)理和組織演化機(jī)制以及熱輥壓過(guò)程中的有限元算法方面系統(tǒng)地分析了高強(qiáng)鋼局部加熱輥壓工藝特點(diǎn);以汽車(chē)用高強(qiáng)鋼方管和橋梁用新型UTU肋兩個(gè)產(chǎn)品為例,進(jìn)行了較全面的有限元模擬分析,明確了不同工藝參數(shù)對(duì)熱輥壓工藝的影響以及與傳統(tǒng)成形工藝特點(diǎn)進(jìn)行了對(duì)比;然后對(duì)這兩個(gè)實(shí)例產(chǎn)品進(jìn)行了裝備開(kāi)發(fā)和試驗(yàn)研究來(lái)闡述高強(qiáng)鋼局部感應(yīng)加熱輥壓成形工藝技術(shù)實(shí)際應(yīng)用領(lǐng)域。通過(guò)對(duì)高強(qiáng)鋼方管輥壓工藝的有限元分析和試驗(yàn)研究,在溫度場(chǎng)中方管獲得了較為理想的溫度分布,且自主設(shè)計(jì)的線型復(fù)合線圈很好滿足了輥壓工藝局部加熱的需求。在對(duì)比的"直接成方"和"圓成方"工藝中,方管圓角處應(yīng)力均超過(guò)1000 MPa;而在"方成方"熱輥壓工藝中,角部應(yīng)力僅100 MPa左右,且截面形狀尺寸精度更高,輥壓成形力更小。在實(shí)驗(yàn)研究中,隨著成形溫度的升高,方管圓角處成形性能得到了明顯改善;當(dāng)成形溫度為650 ℃時(shí),方管角部冷作硬化效應(yīng)明顯減弱,方管壓扁過(guò)程中也沒(méi)有裂紋出現(xiàn)及其角部應(yīng)力集中也獲得了釋放。通過(guò)微觀組織觀察,650 ℃成形時(shí),圓角處的微觀組織為由板條狀貝氏體向粒狀貝氏體發(fā)展,拉伸斷口出現(xiàn)大量拋物線韌窩,說(shuō)明在斷裂前發(fā)生了明顯的塑性形變。在對(duì)UTU肋熱輥壓成形數(shù)值模擬研究中,給出了兩種孔型設(shè)計(jì)方案,分別從金屬流動(dòng)規(guī)律、截面形狀尺寸和軋輥受力特點(diǎn)進(jìn)行了對(duì)比。綜合分析認(rèn)為,"近終型"成形方案更合適輥壓成形工藝;從不同工藝參數(shù)的模擬結(jié)果來(lái)看,當(dāng)成形溫度為900 ℃、單道次壓下量為9 mm時(shí),熱輥壓成形工藝結(jié)果相對(duì)較好。結(jié)合試驗(yàn)研究,與室溫輥壓成形的UTU肋相比,熱輥壓成形后的UTU肋抗疲勞性能大大提高;當(dāng)輥壓溫度在900 ℃～1000 ℃之間,UTU肋端部力學(xué)性能得到一定程度上的改善,微觀組織從初始粗大的鐵素體-珠光體組織轉(zhuǎn)變成等軸超細(xì)化晶粒且彌散分布的細(xì)小的貝氏體和滲碳體顆粒;隨著溫度的升高,(Nb,Ti)(C,N)析出物數(shù)量增加且分布地更加均勻,位錯(cuò)密度急劇下降;微觀斷口形貌出現(xiàn)大尺寸韌窩且伴隨著小尺寸撕裂棱,這與UTU肋具有良好的強(qiáng)韌性能相互印證。
[Abstract]:With the global energy crisis, the design of safety performance of steel structure with increasing serious environmental pressures as well as industry, development and application of advanced high strength steel is the reform trend of the steel industry, is also a common concern of automobile industry and the field of bridge engineering subject. The development of advanced high strength steel and its application in lightweight structure, is in line with modern economy low carbon society, energy saving, safety, the concept of sustainable development and the realization of this idea. The three key technologies: the development and application of high strength steel types, innovative design and optimization of lightweight structure and new manufacturing and forming technology. Despite the many advantages of high strength steel has been popular in the field of automobile industry and bridge engineering, but different from the traditional carbon steel high strength steel, high strength steel high strength at room temperature, the difficulty of forming, forming mechanics behavior and microstructure change of more complex Put forward higher requirements for the equipment and the process of forming, so the traditional preparation process of high strength steel rolling parts is very difficult or impossible to complete. In order to solve the problem of high strength steel into the traditional rolling process caused by the proposed high strength steel induction heating roll forming technology. The traditional rolling deformation, the plastic deformation zone of induction heating to a certain temperature, reduce the forming resistance, improve the forming performance, ensure the workpiece strength without loss and no obvious deformation hardening effect, so as to overcome the problem of high strength steel by rolling faces. This paper from the basic theory of induction heating, roll forming finite element algorithm evolution mechanism and organization mechanism the hot rolling process and the systematic analysis of high strength steel, local heating and rolling process characteristics; to automotive high strength steel square and bridge with the new UTU two rib As an example, makes a comprehensive analysis of finite element simulation, the influence of different parameters on the hot rolling process and traditional forming process characteristics were compared; then the equipment development and Experimental Research on these two examples to explain the products of high strength steel induction heating roll forming technology application field. Through the finite element analysis of the pipe rolling process of high strength steel analysis and experimental research, in the temperature field in tube temperature distribution in the ideal, and the linear composite coil designed can meet the demand of heating and rolling department. In contrast to the "direct" and "self" in the process of square tube the fillet stress was more than 1000 MPa; and in the "prescription" hot rolling process, the stress in the corner is only about 100 MPa, and the cross section shape of high dimensional accuracy, rolling force smaller. In the experimental study, with the The forming temperature, tube fillet forming performance has been significantly improved; when the forming temperature is 650 degrees centigrade, square corner cold hardening effect significantly weakened, in the process of flattening square no cracks and corner stress concentration was also released. Through the microstructure observation, forming 650 DEG C, the microstructure of the fillet on the lath bainite to granular bainite tensile fracture development, the emergence of a large number of parabolic dimples, indicating the obvious plastic deformation before fracture. The UTU fin heat roll forming a numerical study on simulation, gives two kinds of design pass respectively from the laws of the metal flow. Section size and roll force characteristics were compared. The comprehensive analysis, near the end of "forming scheme more suitable roll forming process; simulation results from different process parameters, when the forming temperature is 900 DEG C, single pass The amount of pressure is 9 mm, hot rolling process results is relatively better. Based on experimental study, compared to the UTU rib and room temperature pressure forming roller, anti fatigue performance of UTU rib rolling after heat is greatly improved; when the rolling temperature is between 900 to 1000 DEG C, the end of the mechanical properties of the UTU get a rib the degree of improvement, the microstructure from the initial coarse ferrite and pearlite transformation into bainite and cementite particles of fine and ultra fine grain axial dispersion; with the increase of temperature (Nb, Ti) (C, N) the number of precipitation increases and the distribution is more uniform, dislocation the density decreased sharply; Microfractograph large size dimples and tear ridges with small size, the UTU rib has good strength and toughness properties confirm each other.

【學(xué)位授予單位】：北京科技大學(xué)
【學(xué)位級(jí)別】：博士
【學(xué)位授予年份】：2017
【分類(lèi)號(hào)】：TG306

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 陳俊嶺;李哲旭;舒文雅;李金威;;不同應(yīng)變率下Q345鋼材力學(xué)性能試驗(yàn)研究[J];東南大學(xué)學(xué)報(bào)(自然科學(xué)版);2015年06期

2 米振莉;潘殿軍;江海濤;;700MPa冷軋低合金超高強(qiáng)鋼的典型連續(xù)退火工藝[J];工程科學(xué)學(xué)報(bào);2015年02期

3 Sheng HUANG;Yi-xi ZHAO;Chun-feng HE;;Shear Fracture of Advanced High Strength Steels[J];Journal of Iron and Steel Research(International);2014年10期

4 曹?chē)?guó)富;;圓變方孔型的系數(shù)設(shè)計(jì)法[J];焊管;2014年07期

5 邱林波;劉毅;侯兆新;陳水榮;鐘國(guó)輝;;高強(qiáng)結(jié)構(gòu)鋼在建筑中的應(yīng)用研究現(xiàn)狀[J];工業(yè)建筑;2014年03期

6 李佳;張秀芝;劉建生;;低合金鋼Q345E靜態(tài)再結(jié)晶模型研究[J];大型鑄鍛件;2014年01期

7 FENG Guang-hong;ZHANG Pei;ZHANG Hong-liang;ZHOU Xu-chang;ZHAO Yong;;Numerical Simulation and Experimental Study on Interlock Deformation for Roll Formed U-Section Steel Piling[J];Journal of Iron and Steel Research(International);2013年11期

8 楊文志;閻昱;曹坤洋;王治;;高強(qiáng)度鋼局部加熱輥彎成形分析[J];北方工業(yè)大學(xué)學(xué)報(bào);2013年03期

9 李佳;張秀芝;劉建生;;低合金鋼Q345E高溫?zé)嶙冃涡袨榧皠?dòng)態(tài)再結(jié)晶圖[J];鍛壓技術(shù);2013年04期

10 呂彭民;李大濤;;正交異性鋼橋面板U肋與橋面板焊縫連接處疲勞試驗(yàn)研究[J];鄭州大學(xué)學(xué)報(bào)(工學(xué)版);2013年02期

相關(guān)會(huì)議論文 前1條

1 崔健;陸匠心;張丕軍;;汽車(chē)輕量化研究的進(jìn)展和汽車(chē)用鋼的發(fā)展方向[A];2001中國(guó)鋼鐵年會(huì)論文集（下卷）[C];2001年

相關(guān)博士學(xué)位論文 前4條

1 魏海蓮;中低碳微合金鋼及C-Mn-Al(Si)高強(qiáng)鋼的熱變形行為研究[D];北京科技大學(xué);2015年

2 朱彬;高強(qiáng)鋼熱成形過(guò)程微觀組織及多物理場(chǎng)耦合模擬[D];華中科技大學(xué);2012年

3 馬寧;高強(qiáng)度鋼板熱成形技術(shù)若干研究[D];大連理工大學(xué);2011年

4 謝建斌;金屬及合金在不同介質(zhì)中淬火時(shí)的數(shù)值模擬和應(yīng)用研究[D];昆明理工大學(xué);2003年

相關(guān)碩士學(xué)位論文 前1條

1 高金鳳;熱輥彎成型的熱力耦合有限元分析[D];北方工業(yè)大學(xué);2013年

，

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