摘要
超(超)临界火电机组高温部件用9%￣12%Cr耐热钢的高温蠕变损伤性能对其使用寿命有重要的影响。采用扫描电镜(SEM)、透射电镜(TEM)、X-Ray衍射仪和X-Ray能谱仪等对国产P91钢持久断裂试验前和持久断裂试验后(566℃、170MPa、12493.9h)的试样进行了低温断口、亚结构、第二相类型和成分分析,对P91钢的蠕变损伤性能进行了研究。P91钢在蠕变作用下,马氏体板条发生向亚晶结构的转变,位错密度大大降低,第二相颗粒粗化并聚集,部分合金元素由固溶态向化合态转移,同时析出新相M7C3和laves相Fe2Mo。在持久断裂试验后的试样中并未发现蠕变孔洞的存在,但组织的老化导致硬度的降低。
Degradation of creep properties of 9%～12%Cr heat resistant steel are very important to the life of high-temperature components in uhra-supercritical power units. Creep rupture properties of the domestic P91 steel including low temperature fracture, substructure, the secondary phase and composition analysis were investigated by scanning electronic microscope （SEM）, transmission electron microscope （TEM）, X-Ray diffractometer and X-Ray energy spectrometer, During the creep of P91 steel, subgrain structure is formed at the loss of martensitic laths, the dislocation density is reduced greatly, and the secondary phase particles are coarsened and aggregated, Also, some solid solution alloy elements diffuse and new precipitates, such as M7C3 and laves phase （Fe2Mo）, are precipitated. Creep cavities were not discovered in creep rupture sample （566℃, 170 MPa, 12 493.9 h ）, but the hardness is reduced as a result of the degradation of microstructure.
出处
《中国电力》
CSCD
北大核心
2007年第7期12-16,共5页
Electric Power
基金
国家"十五"重大技术装备研制计划资助项目(00-318-02-01)
关键词
P91钢
蠕变损伤
板条马氏体
位错密度
第二相
P91 steel
creep damage
martensitic lath
dislocation density
secondary phase
