Changes in Microstructure and Mechanical Properties of Cr-Mo Reactor Vessel Steels During Long-Term Service
Changes in Microstructure and Mechanical Properties of Cr-Mo Reactor Vessel Steels During Long-Term Service
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铬钼反应堆容器钢长期使用过程中显微组织和力学性能的变化
DOI：
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发表时间：
1985
期刊：
影响因子：
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通讯作者：
T. B. Cox
中科院分区：
文献类型：
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作者：
Y. Nishizaka;Y. Hara;A. Hori;H. Tsukahara;K. Miyano;T. Wada;T. B. Cox
研究了1Cr-0.5Mo和2.25Cr1Mo钢在长期服役过程中的组织和性能变化。该研究包括对运行了20年的1Cr-0.5Mo钢反应堆容器的检查和对暴露于服务环境的试样的测试。反应堆容器在490 ~ 530/sup 0/C下暴露170，000小时（约20年）后，其室温屈服强度、冲击韧性和蠕变断裂强度与原始性能相比明显下降。服役暴露引起碳化物形态和种类的变化，形成M/sub 2/C和M/sub 7/C/sub 3/碳化物，并将大量的Cr和Mo从基体转移到碳化物中;只有32%的总Mo和72%的总Cr保留在基体中。2.25Cr-1 Mo钢的显微组织比1Cr-0.5Mo钢的稳定性高，但Mo和Cr从基体向碳化物的转移相似。2.25Cr-1 Mo钢基体中残留的Mo和Cr含量在2年暴露后分别仅为钢中总量的25%和74%。Mo和Cr在碳化物中的分配可增加碳化物的稳定性，从而降低基体中的碳含量。基体成分的变化和碳化物形态的变化都会影响合金的力学性能。金相检查提供了关于材料劣化程度的有用信息，尽管在此阶段是定性的。«少
Changes in microstructure and mechanical properties of 1Cr-0.5Mo and 2.25 Cr1Mo steels during long-term service have been investigated. The study includes inspection of a 1Cr-0.5Mo steel reactor vessel which operated for 20 yr and tests on specimens that had been exposed to service environments. The reactor vessel, exposed at 490 to 530/sup 0/C for 170,000 hr (about 20 yr), showed appreciable decrease in the room temperature yield strength, impact toughness and creep rupture strength compared with the original properties. The service exposure caused changes in carbide morphology and species, forming M/sub 2/C and M/sub 7/C/sub 3/ carbides and transferring significant amounts of Cr and Mo from the matrix to carbides; only 32 percent of the total Mo and 72 percent of the toal Cr remained in the matrix. The microstructure of 2.25Cr-1Mo steel showed higher stability than that of 1Cr-0.5Mo steel, although a similar transfer of Mo and Cr from the matrix to carbides took place. The Mo and Cr contents remaining in the 2.25Cr-1Mo steel matrix after a 2yr exposure were only 25 and 74 percent, respectively, of the total quantities in the steel. The partitioning of Mo and Cr to carbides could increase the stability of carbides andmore » consequently reduce the carbon content in the matrix. The mechanical properties are influenced by both the change in the composition of the matrix and the change in carbide morphology. The metallographic examination provides useful information, although qualitative at this stage, on the degree of deterioration of materials.« less