【摘要】：以純鎳N6焊縫為主要研究對象,采用碾壓形變熱處理裝置對純鎳焊縫進(jìn)行碾壓形變熱處理工藝研究,借助光學(xué)顯微鏡(OM)、掃描電鏡(SEM)、顯微硬度計以及靜態(tài)應(yīng)變測量系統(tǒng)等手段分析純鎳焊縫的組織、性能。結(jié)果表明:碾壓形變熱處理溫度從300℃升高到500℃,焊縫抗拉強(qiáng)度從329.62 MPa升高到335.12 MPa,增長了1.7%,焊縫斷后伸長率呈現(xiàn)出先增大后減小的趨勢,400℃時焊縫斷后伸長率最高48.44%,比300℃時焊縫斷后伸長率增長了5.2%。斷后伸長率的增長率高于抗拉強(qiáng)度的增長率,表明碾壓形變熱處理對提高純鎳焊縫塑性十分有效。碾壓形變熱處理可細(xì)化焊縫晶粒,晶粒度從未經(jīng)碾壓形變熱處理時的5.5級升高到平均6.1級;同時有效降低了純鎳焊縫的焊接殘余應(yīng)力,焊縫縱向殘余應(yīng)力σx下降幅度最高達(dá)66.86%,橫向殘余應(yīng)力σy下降幅度最高達(dá)65.87%。綜合分析表明碾壓形變熱處理可以使焊縫組織均勻,細(xì)化晶粒、降低焊縫殘余應(yīng)力,對改善焊縫組織,提高焊縫性能有積極作用,能夠得到純鎳焊縫的高強(qiáng)度、高塑性的良好匹配。
[Abstract]:Taking pure nickel N6 weld as the main research object, the rolling deformation heat treatment device was used to study the rolling deformation heat treatment process of pure nickel weld. The microstructure and properties of pure nickel weld were analyzed by means of optical microscope (OM), scanning electron microscope (SEM), microhardness tester and static strain measurement system. The results show that the tensile strength of the weld increases by 1.7% from 329.62 MPa to 335.12 MPa, when the temperature of rolling deformation heat treatment increases from 300 鈩，

本文編號：2506850