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1、摘要本文以60CrMnMo為研究對象,測量了其試樣在堆焊過程的溫度場和堆焊后的殘余應(yīng)力場。利用ANSYS有限元軟件,建立了模型,對堆焊過程中的溫度場和應(yīng)力場進(jìn)行了數(shù)值模擬。將堆焊試樣的溫度場和殘余應(yīng)力場實(shí)測結(jié)果與模擬結(jié)果進(jìn)行比較,二者基本吻合,證明模型是有效的。在此基礎(chǔ)上,對堆焊試樣溫度場進(jìn)行了數(shù)值模擬,獲得了不同時刻整個試樣的溫度分布及試樣上各典型截面的溫度變化曲線。同時,模擬了在200℃、300℃和400℃不同預(yù)熱溫度條件下,堆焊試樣冷卻到180秒時的溫度場和平衡態(tài)溫度場。模擬結(jié)果表明:無預(yù)熱條件下,試樣冷
2、卻到16秒時移去熱源前后溫度場分布有很大差異,堆焊結(jié)束后,熱量迅速向下表面及周界方向傳播。直至冷卻到180秒,試樣溫度場顯現(xiàn)平衡態(tài)。預(yù)熱可以提高堆焊試樣的整體溫度,并減小側(cè)面和心部的溫差,使堆焊試樣的溫度分布趨于均勻。根據(jù)堆焊溫度場模擬結(jié)果,模擬了無預(yù)熱條件下試樣在堆焊過程中發(fā)生馬氏體相變時幾個關(guān)鍵時刻的瞬態(tài)過程應(yīng)力。同時,還模擬了在200。C、300。C和400℃不同預(yù)熱溫度條件下,堆焊試樣冷卻到180秒時的應(yīng)力場以及殘余應(yīng)力場。結(jié)果表明:在無預(yù)熱條件下應(yīng)力峰值出現(xiàn)于熱影響區(qū)與母材區(qū)交界面,且最大拉應(yīng)力位于試
3、樣內(nèi)部熱影響區(qū)附近。隨預(yù)熱溫度升高,三個典型截面的出現(xiàn)殘余應(yīng)力最大值的位置不變,只是試樣上應(yīng)力分布整體呈下降趨勢。關(guān)鍵詞數(shù)值模擬;溫度場;應(yīng)力場;預(yù)熱溫度燕山人學(xué)工學(xué)碩士學(xué)位論文AbstractThehardfacingspecimenWaStakenfromthehotrollersteel60CrMnMo,whosetemperaturefieldduringhardfacingandresidualstressfieldafterhardfacingweremeasured。ByusingANSYSsof
4、tware,thefiniteelementmodel(FEM)wasestablishedbasedontheweldingplane.Then,thetemperatureandthestressfieldsduringtheprocessofhardfacingweresimulated.Comparingthemeasuredresultsofthetemperatureandresidualstressfieldswiththosesimulatedones,theyarekeepagreementv
5、erywell,whichprovethismodelforthehardfacingsimulationiseffective.Basedonmentionedabove,thetemperaturefieldofthespecimenduringhardfacingWassimulated、Thetemperaturedistributionofthespecimenatthedifferenttimesandcu/'vesofthetemperaturedistributionatdifferentsec
6、tionwereobtained.Meanwhile,thetemperaturefieldofthehardfacingspecimen,whichwascooledto180s,anditsbalancestatetemperaturefieldweresimulatedwhenthepreheatingtemperaturewere200℃。300。Cand400℃respectively.ThesimulatedresuJtsofthetemperatureshowthat,thetemperature
7、distributionbeforeandafterthespecimenwascooledto16sisdifferentlargely.Thequantityofheattransmitstobelowsurfacequickly.Whenthespecimeniscooledtol80s,thetemperaturefieldbecamebalancestate.Thetemperatureofthespecimencarlbeincreasedandthetemperaturedifferencebet
8、weencenterandthesidesurfaceCanbereducedbypreheating,whichmakestemperaturedistributionofthespecimenuniform.Accordingthemodelandsimulatedresultsofthetemperaturefield,severalprocessstressfieldsatth