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本文调查了,NiCrMoV转子钢不同显微组织(马氏体相对于贝氏体)对塑脆转变温度的影响。在相同的原妇奥氏体晶粒度和硬度条件下,贝氏体组织具有较高的塑脆转变温度。改变杂质水平,看出显微组织的影响与回火脆性无关。对这种普遍观查到的在塑脆转变温度和韧性上的差别可能的原因进行了分析,并认为是由于碳化物的尺寸及分布上的差别造成。在同样晶粒度和硬度,不添加杂质的条件下,马氏体有较低的屈服强度、较高的冲击断裂功以及较低的塑脆转变温度,这些都由于较细的平均碳化物尺寸引起。这种屈服强度的差别可能按照Orowan的强化机制加以说明。
In this paper, we investigated the effects of different microstructures (martensite vs. bainite) on the transition temperature of plastic deformation in NiCrMoV rotor steel. Under the same austenite grain size and hardness conditions, bainite has a higher plastic-brittle transition temperature. Change the impurity level, see the impact of microstructure has nothing to do with the temper brittleness. The possible reason for the difference in the transition temperature and ductility between plastic transitions and brittle transitions was analyzed and considered to be due to the differences in the size and distribution of carbides. In the same grain size and hardness, without adding impurities, martensite has a lower yield strength, higher impact fracture work and lower plastic transition temperature, these are due to the smaller average carbide size cause. This difference in yield strength may be explained by Orowan’s hardening mechanism.