GH536鎳基高溫合金焊接組織演變
發(fā)布時間:2018-04-23 15:02
本文選題:GH + 鎳基高溫合金 ; 參考:《航空材料學報》2015年06期
【摘要】:使用體視顯微鏡、光學顯微鏡、掃描電鏡及其能譜儀對GH536焊接接頭組織進行分析,結(jié)果表明:固溶態(tài)GH536由γ基體、大量M6C及少量M23C6組成;焊后,大量M6C在晶內(nèi)彌散析出,在晶界和孿晶界上不連續(xù)析出,原有的碳化物長大。熱影響區(qū)分為三個區(qū)域:靠近母材處,存在粗大"島鏈狀"碳化物;中部,部分碳化物重新固溶入基體,存在"網(wǎng)鏈狀"碳化物;靠近熔合線,存在碳化物貧化區(qū)。焊縫處碳化物在晶界和枝晶間析出,從邊緣到中心逐漸凝固:初始階段,組織為非外延式生長的胞狀晶,生長方向垂直于熔合線;中間階段,組織轉(zhuǎn)變?yōu)橹鶢顦渲?且越靠近焊縫中心,晶粒尺寸越大;中心為粗大的等軸狀樹枝晶。焊接過程中,焊縫金屬中各元素未損失。
[Abstract]:The microstructure of GH536 welded joints was analyzed by stereoscopic microscope, optical microscope, scanning electron microscope and energy dispersive spectrometer. The results show that the solid solution GH536 consists of 緯 matrix, a large amount of M6C and a small amount of M23C6, and after welding, a large amount of M6C is dispersed in the crystal. Discontinuous precipitation occurs at grain boundaries and twin boundaries, and the original carbides grow up. The thermal effect can be divided into three regions: near the base metal, there are coarse "island chain" carbides; in the middle, some carbides are re-dissolved into the matrix, and there are "network" carbides, and near the fusion line, there are carbides depleted areas. The carbides in the weld are precipitated between grain boundaries and dendrites, and solidified gradually from the edge to the center: in the initial stage, the microstructure is a non-epitaxial cellular crystal, the growth direction is perpendicular to the fusion line, and in the intermediate stage, the microstructure changes to a columnar dendrite. The bigger the grain size is, the bigger the equiaxed dendrite is. During the welding process, the elements in the weld metal are not lost.
【作者單位】: 北京航空材料研究院;中航工業(yè)失效分析中心;航空材料檢測與評價北京市重點實驗室;
【分類號】:TG407
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本文編號:1792455
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