新型20Cr11MoVNbNB耐热钢的高温性能

The High-temperature Properties of 20Cr11MoVNbNB Heat Resisting Steel

本文研究了新型２０Ｃｒ１１ＭｏＶＮｂＮＢ耐热钢的高温持久硬度和５５０℃不同应力下的蠕变．结果表明：该钢的持久硬度ＨＢ与温度、保载时间综合参数Ｐ＝Ｔ（２０＋ｌｇｔ）之间，以Ｐｃ≈２０．３×１０３为界，存在两段不同斜率的线性关系，并得出相应的直线方程，利用所得方程，可以很方便地由短期高温持久硬度推测低温长期持久硬度同时导出了该钢在５５０℃时的蠕变应力与蠕变速度的关系，求出了εⅡ＝１０－７％／ｈ时的蠕变极限．

This paper deals with the high- temperature durable hardness and the creep under the condition of different stresses at 550t of 20Cr11Mo NbNB heat resisting steel. The Results show that two sectional linear relations with different slopes between durable hardness (HB) and the temperature-time combined parameter P = T (20 + lgt) are present, to take P≈20. 3 ×103 as Critical Value. With these linear relations, the low-temperature long age durable hardness can be extrapolated by high-temperature short age durable hardness, the relation between the creep stresses and Creep ratio of the steel at 550t is obtained, when εⅡ≈10 -7 %/h, the creep limit stress (of) of the steel at 550t is approximately equal to 60 MPa.