【摘要】：焊接過(guò)程中,焊核區(qū)內(nèi)構(gòu)件將經(jīng)歷劇烈的高溫作用并產(chǎn)生極大的塑性應(yīng)變,這種變形是極其不均勻的。在不均勻的形變作用下,結(jié)構(gòu)將產(chǎn)生焊接熱應(yīng)力并最終形成焊后殘余應(yīng)力,影響構(gòu)件的強(qiáng)度及疲勞壽命。工程中為了降低構(gòu)件在焊接制造過(guò)程中產(chǎn)生的焊接殘余應(yīng)力,常采用熱處理的方式對(duì)焊后殘余應(yīng)力進(jìn)行消除。本文首先采用順序熱力耦合方法,運(yùn)用有限元軟件ABAQUS及其子程序?qū)附舆^(guò)程進(jìn)行模擬。研究中對(duì)比分析了FSW、TIG焊接過(guò)程的溫度場(chǎng)、焊后殘余應(yīng)力場(chǎng),討論了熱輸入功率對(duì)兩種焊接方式的影響,并對(duì)焊后殘余應(yīng)力進(jìn)行了熱處理。計(jì)算結(jié)果表明：FSW焊接過(guò)程峰值溫度為1062℃,遠(yuǎn)低于TIG焊接的1683℃,僅為熔點(diǎn)溫度70%；焊核區(qū)內(nèi)FSW焊接拉伸應(yīng)力數(shù)值低、分布范圍小,深度方向上應(yīng)力呈下降趨勢(shì),較TIG焊接更為合理；增大兩種焊接方式的熱輸入,焊后殘余應(yīng)力均有略微下降；焊后熱處理可以有效的降低焊接殘余應(yīng)力,熱處理溫度越高,降低效果越明顯。本文還在平板焊接的基礎(chǔ)上,進(jìn)行了工程壓縮機(jī)葉輪的焊接計(jì)算。在對(duì)焊接過(guò)程的模擬分析中,研究了葉輪焊接的溫度場(chǎng)、焊接殘余應(yīng)力場(chǎng),并討論了葉輪幾何尺寸對(duì)焊接過(guò)程的影響。隨后為了降低葉輪內(nèi)的焊后殘余應(yīng)力,以保證正常服役過(guò)程中的強(qiáng)度及疲勞性能,進(jìn)行了焊后熱處理計(jì)算,系統(tǒng)研究了焊后熱處理溫度、熱處理保溫時(shí)間等工藝參數(shù)對(duì)降低焊后殘余應(yīng)力的影響。計(jì)算結(jié)果表明：葉輪焊接溫度場(chǎng)集中于焊道兩側(cè),遠(yuǎn)離焊縫位置各點(diǎn)溫升并不明顯,葉片延焊接方向焊后拉伸殘余應(yīng)力峰值將達(dá)到1138MPa,垂直焊接方向殘余應(yīng)力也將達(dá)到783.9MPa；輪盤(pán)厚度越大,熱應(yīng)變?cè)叫?焊后殘余應(yīng)力越大；葉片厚度增大,熱應(yīng)變減小,焊后殘余應(yīng)力出現(xiàn)不規(guī)律變化；焊后熱處理有效的降低了焊后葉輪內(nèi)的殘余應(yīng)力,熱處理溫度越高,殘余應(yīng)力越低,但當(dāng)溫度過(guò)高時(shí),葉片邊緣與輪盤(pán)接觸位置將因過(guò)度變形產(chǎn)生不合理的應(yīng)力集中；保溫時(shí)間越長(zhǎng),應(yīng)力松弛效果越好,焊后殘余應(yīng)力降低越明顯。
[Abstract]:In the welding process, the components in the welding core zone will undergo severe high temperature action and produce great plastic strain, which is extremely uneven. Under the action of uneven deformation, the structure will produce welding thermal stress and finally form the residual stress after welding, which will affect the strength and fatigue life of the component. In order to reduce the welding residual stress of components in the process of welding and manufacturing, heat treatment is often used to eliminate the residual stress after welding. In this paper, the sequential thermodynamic coupling method is used to simulate the welding process by using the finite element software ABAQUS and its subroutine. In the study, the temperature field and residual stress field of FSW,TIG welding process are compared and analyzed, the influence of heat input power on the two welding methods is discussed, and the residual stress after welding is heat treated. The results show that the peak temperature of FSW welding process is 1062 鈩，

本文編號(hào)：2481655