粗晶对2Cr12NiMo1W1V钢性能的影响

测试了直径为135 mm的粗晶2Cr12NiMo1W1V圆钢不同位置的室温和高温拉伸、冲击、硬度、蠕变持久性能,并与细晶2Cr12NiMo1W1V钢性能进行了对比。结果表明,在不同位置取样测定的各项性能比较均匀,且均满足标准要求;粗晶材料的室温拉伸、冲击等性能有一定富裕度,但与细晶材料相比还存在较大差距;粗晶材料的高温拉伸和蠕变持久性能优异,特别是蠕变持久性能远好于细晶材料。

高参数汽轮机螺栓用高温合金材料研究

文章介绍了国内外高参数汽轮机高温螺栓用高温合金材料的特性,重点分析了这些合金的线膨胀系数、高温强度、高温蠕变持久强度等材料性能,及螺栓断裂失效案列,为国内高参数超超临界汽轮机用高温螺栓的选材和预防断裂提供建议。

Influence of long-term isothermal aging on microstructure and creep rupture properties of Ni-base superalloy M4706

After a standard heat treatment,the microstructural evolution with time during isothermal aging at 850°C and its effect on the creep rupture properties of the Ni-base superalloy M4706 at 870°C and 370 MPa are investigated.It is found that as the aging time increases from 0 to 5000 h,the average diameter of coarseγ′increases from 241 to 484 nm,and the distribution of the carbides at grain boundaries changes from discontinuous to continuous.Moreover,experimental observations on the microstructures of all the crept specimens reveal that dislocation bypassing controls the creep deformation.Thus,it is concluded that the transitions in the microstructures result in the degeneration of the creep rupture properties of the experimental alloy with aging time.

某燃气轮机涡轮叶片长期服役后的微观组织与性能

研究了服役45000 h后的燃气轮机叶片不同部位微观组织与持久性能的退化行为。试验结果表明:长时服役后,叶片榫齿部位的微观组织未发生明显的退化损伤,叶片叶尖部位的微观组织则发生明显的退化,其中MC型碳化物发生退化分解,立方状γ′相退化成粗大的球状γ′相。长时服役后,叶片的硬度没有发生明显的变化,而蠕变持久性能明显降低,该燃气轮机叶片在850℃下10^(5) h的外推持久强度降低至66.72 MPa。