水蒸气温度和流量对T91钢氧化行为的影响

Effect of Water Vapor Temperature and Flow on Oxidation Behavior of T91 Heat Resisting Steel

研究了高温水蒸气的温度和流量对T91钢氧化行为的影响,阐述了氧化层的组织结构与氧化动力学之间的关系。结果表明:水蒸气氧化过程分为线性的初始快速氧化阶段和之后的抛物线慢速氧化阶段及线性的慢速氧化阶段。当水蒸气温度较高、流量较小时出现慢速氧化阶段。初始快速氧化阶段的氧化速率随水蒸气温度的升高而增大,但水蒸气流量对初始快速氧化阶段的氧化速率影响很小。初始快速氧化阶段单位面积增重最大值随水蒸气流量的增大而线性增大,且随温度升高而增速加快。随着水蒸气温度和流量的增加,T91钢最外层氧化层的形态发生明显改变,导致抗高温氧化性能显著下降。

The effects of water vapor temperature and flow on oxidation behavior of T91 heat resisting steel was studied to reveal the relation between oxidation kinetics and scale structure.The results indicate that oxidation processes are divided into linear stage of rapid oxidation,parabolic stage of slow oxidation and linear stage of slow oxidation.Linear stage of slow oxidation takes place at the high temperature and small flow of water vapor.Oxidation rate increases with increasing vapor temperature in the fast oxidation of T91 steel.However,the effects of flow on the fast oxidation are not evident.The maximum of mass gain shows a linear increase with increasing flow,and the high vapor temperature accelerates this trend.The morphology change of outer layer causes the rapid decreasing of high temperature oxidation resistance with increasing the temperature and the flow of the water vapor.