研究了热老化对核级316LN锻造奥氏体不锈钢的位错组态、电阻率及显微硬度的影响规律。结果表明，随着热老化的进行，奥氏体基体中位错密度总体下降，而始于晶界向晶内延伸的扩展位错数量增多且宽度变窄，其中，固溶态的扩展位错宽度约为1.0 m，热老化5000 h后约为0.2 m。分析认为，碳原子在晶界及其附近微区的偏聚是引起位错亚结构变化的主要原因；电阻率随热老化时间的延长、检测温度的升高而增大，且热老化5000 h后电阻率随温度的增长速率高于固溶态；晶内和晶界处的显微硬度值随热老化的进行均有所升高，二者之间显微硬度的差值逐渐增加。%The influence of the thermal aging on dislocation configuration, electrical resistivity and hardness of nuclear grade 316LN forged austenitic stainless steel is studied in this paper. The results show that, as the thermal aging proceeds, the total dis-location density in the austenite matrix decreases. The number of extended dislocations which begins at grain boundary and subse-quently extends to the intragranular is also found to increase with the reduction of the width of the extended dislocation. The dis-location width in the solid solutions is approximately 1.0 m, while after 5 000 h thermal aging the width decreases down to around 0.2 m. The segregation of carbon atoms in and near the grain boundaries might account for the change in dislocation structure. Electrical resistivity also increases with thermal aging time and temperature. After 5 000 h thermal aging the electrical resistivity with temperature increases more rapidly compared with that in the solute state. The micro-hardness of the structures located at in-tragranular and grain boundary is enhanced with thermal aging, however, the micro-hardness difference increases.
展开▼
