CAJ | 학술논문

异种钢焊接接头常应用于高温下工作的大型构件，其蠕变特性和持久性能对结构的安全性具有重要意义。常规的蠕变试验和高温持久试验仅适用于均匀材料，对非均匀的异种钢接头存在局限性。为了解决该问题，针对某种构件上采用的含有过渡层的马氏体钢与珠光体钢异种金属接头进行了有限元建模。分别利用 K-R 蠕变损伤模型和改进的θProjection 模型进行模拟计算，并且对比了非均匀结构与均匀的焊缝、过渡层和母材的蠕变特性。对比发现，非均匀结构中抗蠕变性能较弱的过渡层部分的蠕变速率要大于均匀的过渡层材料的蠕变速率，这说明材料的不均匀性会带来附加的蠕变损伤。因此，仅通过均匀材料的蠕变试验来预测非均匀结构的寿命是不可靠的，应采用蠕变试验与有限元计算相结合的方法进行非均匀结构的寿命预测。
이충강한접접두상응용우고온하공작적대형구건，기연변특성화지구성능대결구적안전성구유중요의의。상규적연변시험화고온지구시험부괄용우균균재료，대비균균적이충강접두존재국한성。위료해결해문제，침대모충구건상채용적함유과도층적마씨체강여주광체강이충금속접두진행료유한원건모。분별이용 K-R 연변손상모형화개진적θProjection 모형진행모의계산，병차대비료비균균결구여균균적한봉、과도층화모재적연변특성。대비발현，비균균결구중항연변성능교약적과도층부분적연변속솔요대우균균적과도층재료적연변속솔，저설명재료적불균균성회대래부가적연변손상。인차，부통과균균재료적연변시험래예측비균균결구적수명시불가고적，응채용연변시험여유한원계산상결합적방법진행비균균결구적수명예측。
Dissimilar welded joints are often used in large components working under high temper-ature.The creep rupture property of dissimilar welded joint is of great significance for the safety of the structure.Conventional creep test and creep rupture test are only applicable to homogeneous ma-terials,but not to inhomogeneous materials.In order to solve this problem,a finite element model was built according to a dissimilar welded joint used in a real component which made up of martensitic steel and pearlitic steel.By using K-R creep damage model and advancedθProjection model respective-ly,it is found that the creep rupture property of inhomogeneous dissimilar joint is different from that of homogeneous base metal,weld metal and transition layer.The creep rate of transition layer in dis-similar joint is higher than the same homogeneous material,which means the heterogeneity of struc-ture leads to additional creep damage.The conclusion can be made that it is unreliable to predict the creep life of a dissimilar steel structure only according to creep rupture tests on different parts for ho-mogenous materials,the finite elements analysis based on creep rupture test is also necessary.