蒸汽温度对T91钢氧化动力学的影响

Steam Oxidation Dynamics of T91 Steel Under Different Temperatures

采用热分析天平连续称重法对T91钢550～750℃水蒸气氧化动力学进行了研究.在水流量为290～305 mLh-1的高温蒸汽下,发现T91钢氧化动力学低于670℃服从抛物线规律,670～700℃是过渡区,700℃以上服从双直线规律;T91钢在550～668℃下抗水蒸气氧化性好,随时间延长氧化速率均减小,随温度升高腐蚀加重;T91钢在超过670℃以上的高温水蒸气下其慢速阶段的氧化速率随时间延长不变,其值达到2级抗氧化性标准(0.1～1 gm-2h-1),抗氧化性能较差.

The Thermal Gravimetric Analysis was used to study the oxidation kinetics of T91 steel. In high temperature steam with flux of 290～305 mL per hour, T91 steel oxidation showd the following facts：First,670～700 ℃ was a transition region of oxidation; In temperatures below 670℃, oxidation generally abided by parabolic oxidation kinetics and ones above 700℃, it comformed to double straight line. Second,with extension of aging, the oxidation speed of T91 steel gradually reduced within 550～668 ℃. Third, under the temperatures above 670℃ ,the oxidation resistance reached level 2 of standard and oxidation speed was constant in the period of slow oxidation; Therefore,the oxidation resistance was not good.