为了研究T91钢焊接接头服役老化行为，采用OM、SEM 、显微硬度以及微型杯突试验对服役前和服役两年后的 T 91钢焊接接头进行了研究．结果表明服役前后组织变化不大，组织都是回火马氏体＋少量的铁素体，晶粒度大小差异不大，组织都较为均匀；服役后的焊接接头的显微硬度较服役前低；比屈服强度降低9％、比抗拉强度降低11％、比断裂能降低13．5％；服役前后的断口有大小不一，深浅不同的韧窝，但服役前后的断口并没有明显不同，服役前后都是韧性断裂．%In order to study aging behavior of welded joints of T 91 steel .The microstructure and property of the welded joints after 2 year service were researched by OM ,SEM ,Vickers hardness test and small punch test (SPT) .The microstructure of welded joints of T91 steel after service became coarse and the grain boundary became vague .More carbide particles were observed in welded joints after service .The microhardness gradient curve of the welded joints before service was higher than that after service .Compared with those befor service ,ratios of yield strength ,tensile strength and fracture energy after serviced were reduced for 9% ,11% and 13 .5% respectively .The SEM fracture appearance of SPT specimens was the characteristic of ductile fracture ,irrespectively before or after service ,though the dimple size was a little bit big and deep before service and some cluster particles were observed after service for the ripening of carbides .
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