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球軸承滾動(dòng)體螺旋孔型斜軋宏微觀變形與損傷行為研究

發(fā)布時(shí)間:2018-09-02 08:32
【摘要】:滾動(dòng)軸承是高速鐵路、高速精密機(jī)床和冶金軋機(jī)等重大裝備技術(shù)領(lǐng)域的核心配套部件之一。但目前國(guó)內(nèi)生產(chǎn)的滾動(dòng)軸承還無(wú)法較好的滿足上述重大裝備領(lǐng)域高速、重載等惡劣服役工況。滾動(dòng)體作為滾動(dòng)軸承關(guān)鍵組件,其成形制造技術(shù)水平直接影響著滾動(dòng)軸承的動(dòng)態(tài)性能、可靠性和服役壽命。螺旋孔型斜軋(斜軋)是目前生產(chǎn)軸承滾動(dòng)體零件的一種優(yōu)質(zhì)、高效塑性加工技術(shù)。但斜軋工藝設(shè)計(jì)和變形機(jī)理復(fù)雜,成形精度和組織性能也還缺乏科學(xué)、有效的調(diào)控方法,都致使其無(wú)法較好的服務(wù)于高性能滾動(dòng)體的成形制造。本文以鋼球滾動(dòng)體的熱斜軋成形為研究對(duì)象,通過(guò)解決建模仿真中軋輥精確建模方法、仿真平臺(tái)選擇、軋件畸變、網(wǎng)格劃分、求解參數(shù)設(shè)置等關(guān)鍵技術(shù)問(wèn)題,基于SIMUFACT建立了軸承鋼球熱斜軋三維宏微觀有限元仿真模型。基于模擬結(jié)果,揭示了鋼球熱斜軋成形過(guò)程塑性應(yīng)變、溫度、軋制力能參數(shù)、相對(duì)滑動(dòng)與磨損、動(dòng)態(tài)再結(jié)晶、靜態(tài)再結(jié)晶和晶粒尺寸等宏微觀變形規(guī)律。針對(duì)鋼球熱斜軋心部損傷,通過(guò)研究應(yīng)力場(chǎng)的分布和演變特征闡明心部損傷是心部區(qū)域較高水平的橫向拉應(yīng)力、循環(huán)交變的剪切應(yīng)力和多向拉應(yīng)力為主的負(fù)靜水壓應(yīng)力狀態(tài)共同作用的結(jié)果。在此基礎(chǔ)上,從不考慮靜水壓應(yīng)力下?lián)p傷增長(zhǎng)和基于Zener-Hollomon系數(shù)耦合變形溫度與應(yīng)變速率影響兩個(gè)方面,改進(jìn)了Lemaitre損傷模型。同時(shí)進(jìn)一步借助SIMUFACT二次開(kāi)發(fā)技術(shù),將改進(jìn)損傷模型嵌入到有限元模型中,建立了鋼球熱斜軋損傷預(yù)測(cè)模型。軋輥軋制孔型和軋制工藝參數(shù)對(duì)鋼球熱斜軋作用機(jī)制的研究結(jié)果表明:本文提出的冪指函數(shù)凸棱高度變化特征孔型方案能軋制出成形精度更高、晶粒尺寸更細(xì)的球坯;過(guò)高或過(guò)低的軋制溫度和過(guò)大或者過(guò)小的軋輥傾角均會(huì)降低軋制成形精度;球坯晶粒尺寸和軸心區(qū)域損傷均對(duì)軋制溫度較為敏感,隨軋制溫度的升高,晶粒尺寸呈現(xiàn)顯著的粗化,心部損傷程度大幅增加。研究結(jié)果能為鋼球滾動(dòng)體熱斜軋的控形與控性成形提供有效指導(dǎo)。
[Abstract]:Rolling bearing is one of the core parts of high-speed railway, high-speed precision machine tool and metallurgical mill. But at present, the rolling bearings produced in our country can not meet the high speed, heavy load and other bad service conditions. As the key component of rolling bearing, the level of forming and manufacturing technology directly affects the dynamic performance, reliability and service life of rolling bearing. Spiral pass cross rolling (cross rolling) is a kind of high quality and high efficiency plastic machining technology for producing bearing rolling parts. However, the cross rolling process design and deformation mechanism are complex, the forming accuracy and microstructure and properties are also lack of scientific, effective control methods, so that it can not be a better service for the forming and manufacturing of high performance rolling body. In this paper, the hot cross rolling forming of steel ball rolling body is taken as the research object. By solving the key technical problems in modeling and simulation, such as the precise modeling method of roll, the selection of simulation platform, the distortion of rolling piece, the mesh division, the solution of parameter setting, etc. Based on SIMUFACT, a three-dimensional macro-micro finite element simulation model for hot cross rolling of bearing steel balls is established. Based on the simulation results, the macro and micro deformation rules such as plastic strain, temperature, rolling force and energy parameters, relative sliding and wear, dynamic recrystallization, static recrystallization and grain size were revealed. In view of the damage to the center of hot cross rolling steel ball, the distribution and evolution characteristics of stress field are studied. It is shown that the damage of the center is a high level of transverse tensile stress in the center region. The result of the interaction between cyclic shear stress and multi-direction tensile stress in the negative hydrostatic stress state. On this basis, the damage growth under hydrostatic stress and the influence of deformation temperature and strain rate based on Zener-Hollomon coefficient are taken into account to improve the damage model of Lemaitre. At the same time, the improved damage model is embedded into the finite element model with the help of SIMUFACT secondary development technology, and the damage prediction model for hot cross rolling of steel balls is established. The effect of rolling pass and rolling process parameters on hot cross rolling of steel ball is studied. The results show that the feature pass scheme proposed in this paper can roll the billet with higher forming precision and finer grain size. Too high or too low rolling temperature and too large or too small roll inclination angle will reduce the rolling forming precision, the grain size and the damage in the axial zone of the ball blank are sensitive to the rolling temperature, and the rolling temperature increases with the increase of rolling temperature. The grain size showed obvious coarsening and the degree of heart damage increased significantly. The results can provide effective guidance for shape control and controlled forming of rolling body.
【學(xué)位授予單位】:武漢理工大學(xué)
【學(xué)位級(jí)別】:碩士
【學(xué)位授予年份】:2015
【分類(lèi)號(hào)】:TG335.17;TH133.3

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 華林;錢(qián)東升;;軸承環(huán)軋制成形理論和技術(shù)[J];機(jī)械工程學(xué)報(bào);2014年16期

2 Zbigniew Pater;;Multi-Wedge Cross Rolling of Balls[J];Journal of Iron and Steel Research(International);2013年10期

3 楊立芳;葉軍;;高速加工中的機(jī)床主軸軸承技術(shù)[J];軸承;2012年01期

4 張俊江;;高端軸承裝備制造業(yè)的發(fā)展機(jī)遇[J];軸承;2011年12期

5 楊曉蔚;;高速鐵路軸承概述[J];軸承;2011年10期

6 龐于思;;斜軋白口鑄鐵球狀體分層和貼皮的分析[J];河南冶金;2011年04期

7 楊曉蔚;伍海云;;滾動(dòng)軸承對(duì)滾動(dòng)體的技術(shù)要求[J];軸承;2010年08期

8 王寶雨;王少臣;胡正寰;周永平;;冷斜軋磷銅球溫度場(chǎng)的數(shù)值模擬[J];鍛壓技術(shù);2008年04期

9 周永平;王寶雨;胡正寰;;斜軋磷銅球成形過(guò)程的數(shù)值模擬[J];北京科技大學(xué)學(xué)報(bào);2008年02期

10 劉橋方,嚴(yán)楓;我國(guó)軸承制造技術(shù)的現(xiàn)狀及其發(fā)展趨勢(shì)[J];軸承;2005年06期

相關(guān)碩士學(xué)位論文 前2條

1 張瑞;GCr15軸承鋼在熱環(huán)軋過(guò)程中的再結(jié)晶行為研究[D];武漢理工大學(xué);2014年

2 李波;鋼球縱軋成形法連軋關(guān)系的研究及有限元數(shù)值模擬[D];燕山大學(xué);2005年

,

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