The paper deals with the effect of the morphology characteristics, grain size, and the volume fraction of AlN- and NbC-precipitated particles on the prior austenite grain growth behavior in the Al- and Nb-microalloying 20MnCr gear steel during pseudo-carburizing heat treatments. The results indicate that the Nb addition in 20MnCr gear steel have a better effect on preventing austenite grain growth. The coarsening time after pseudo-carburizing in the Nb-microalloyed 20MnCr steel are improved by about 4 h compared with the Al-microalloyed steel. The precipitated particles coarsen and the number decreases with the pseudo-carburization temperature increasing, resulting in a reduction in the pinning pressure of the precipitated particles on the austenite grain boundaries. When the pseudo-carburization temperature reaches 1150 °C, the precipitated particles no longer have the ability to pin the austenite grain boundaries. In addition, the kinetics model for austenite grain growth under the process of the pinning and coarsening of the precipitated particles was established.

中文翻译：

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析出颗粒对Al、Nb微合金化20MnCr齿轮钢奥氏体晶粒长大的影响

本文研究了AlN和NbC微合金化20MnCr齿轮钢在假渗碳热处理过程中形貌特征、晶粒尺寸和AlN和NbC沉淀颗粒的体积分数对原奥氏体晶粒长大行为的影响。 。结果表明，20MnCr齿轮钢中添加Nb对于阻止奥氏体晶粒长大有较好的效果。 Nb微合金化20MnCr钢假渗碳后的粗化时间比Al微合金钢提高了约4 h。随着拟渗碳温度的升高，析出颗粒粗大化，数量减少，导致析出颗粒对奥氏体晶界的钉扎压力降低。当假渗碳温度达到1150℃时，析出颗粒不再具有钉扎奥氏体晶界的能力。此外，还建立了析出颗粒钉扎和粗化过程中奥氏体晶粒长大的动力学模型。