论文部分内容阅读
通过OM、SEM和TEM显微组织观察以及洛氏硬度测量,研究了固溶温度和时间以及时效时间对两种成分(加Cr和不加Cr)NAK80实验钢组织和硬度的影响规律。结果表明:时效时间对预硬化硬度影响很大,薄规格(30 mm)和厚规格(70 mm)实验钢均在时效6 h时达到峰值硬度;在一定范围内升高固溶温度和延长固溶时间对硬度的提升作用非常小。实验钢时效处理后的组织主要是粒状贝氏体+析出相,薄规格加Cr成分还存在一些板条贝氏体。TEM分析表明,析出相主要由ε-Cu和Ni-Al强化相组成,以单独或复合的形式在晶界处大量析出。
The effects of solution temperature, aging time and aging time on the microstructure and hardness of the two components (plus and minus Cr) NAK80 were investigated by OM, SEM and TEM microstructure observation and Rockwell hardness measurement. The results show that the aging time has a great influence on the pre-curing hardness. The thin-gauge (30 mm) and the thick-gauge (70 mm) experimental steels all reach the peak hardness at 6 h after aging. Solvent time to enhance the role of hardness is very small. The microstructure of the experimental steel after aging treatment is mainly granular bainite + precipitated phase. There are also some lath bainite in the thin gauge plus Cr composition. TEM analysis shows that the precipitates mainly consist of ε-Cu and Ni-Al strengthening phases, which precipitated in the grain boundaries either singly or in combination.