论文部分内容阅读
介绍了在含氮量接近质量分数28%的高氮奥氏体中出现的一种特殊的中温转变现象。在奥氏体晶界和晶内萌生细小的分解核心,在核心内可以看到更细小的析出物,随后分解核心长大十分缓慢而核心的数量不断增加,最终各个细小的分解核心连成一片,形成高度弥散的分解产物,在其上分布着大量细小析出物,明显不同于马氏体或下贝氏体的针片状组织。分解产物的硬度高达900HV左右,明显高于回火马氏体的硬度。这种高氮奥氏体的等温分解过程有相当长的孕育期,随后分解量随时间的延长而增加,最终可达100%分解。初步观察的结果表明,其组织形貌和转变动力学都与贝氏体转变或马氏体转变有明显的区别。
A special phenomenon of mid-temperature transformation in high nitrogen austenite with a nitrogen content close to 28% mass fraction is introduced. In the austenite grain boundaries and grain initiation small decomposition of the core, you can see in the core of smaller precipitates, and then break up the core grow very slowly and the core of the increasing number of each final small decomposition into a core , The formation of highly dispersed decomposition products, distributed in a large number of small precipitates, significantly different from the martensite or bainite needle-like tissue. Decomposition products hardness up to about 900HV, significantly higher than the hardness of tempered martensite. This high nitrogen austenite isothermal decomposition process has a very long incubation period, then the amount of decomposition increases with time, eventually up to 100% decomposition. Preliminary observations show that the morphology and transformation kinetics of the bainite transformation or martensite transformation are significantly different.