ABSTRACT The ferritic ductile cast iron, SiMo51, with graphite nodules and grain boundary carbides, was tested at 700°C with respect to creep, uniaxial strain and oxidation, investigating the internal damage evolution. Creep curves, with total lives of 65–339 days, show a short primary creep followed by predominantly tertiary creep displaying two stages. The first was associated with cavitation around carbides and nodules with a short initial effect from oxidation. The second was associated with the formation of cracks through linking of elongated voids. Misorientation maps demonstrate local dislocation activity during creep and tensile testing. Oxidation tests, between 15 min and 2 weeks, show that three oxide layers are formed and that an innermost precipitation zone of SiO2 is present in the initial stage. Elemental line scans, compared with thermodynamic calculations, suggest the layers are FeO with precipitates of SiO2 and/or Fe2SiO4, FeO without precipitates, and Fe2O3.

中文翻译：

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700°C 时铁素体球墨铸铁 SiMo51 的蠕变、应变和氧化损伤

摘要 具有石墨球和晶界碳化物的铁素体球墨铸铁 SiMo51 在 700°C 下进行蠕变、单轴应变和氧化测试，研究内部损伤演变。蠕变曲线，总寿命为 65-339 天，显示一个短暂的初级蠕变，然后是主要的三次蠕变，显示两个阶段。第一个与碳化物和结核周围的空化有关，氧化作用的初始影响很短。第二个与通过连接细长空隙形成裂纹有关。错误取向图展示了蠕变和拉伸试验期间的局部位错活动。15 分钟到 2 周之间的氧化测试表明，形成了三个氧化层，并且在初始阶段存在最内部的 SiO2 沉淀区。元素线扫描，