铜含量对高铬铁素体钢组织和蠕变性能的影响

对含不同质量分数(0,0.6%,3%)铜的高铬铁素体钢在650℃和140MPa条件下蠕变前后的组织和蠕变性能进行了研究。结果表明:随着铜含量从0提高3%,钢的蠕变断裂时间从1172h提高到1 620h,蠕变速率从2.2×10-9s-1降低到1.2×10-9s-1;铜的添加有效抑制了对蠕变性能不利的高温δ铁素体相的形成;添加3%铜的试验钢基体内弥散析出了大量尺寸为50～100nm的富铜相,有效抑制了位错的运动,从而提高了该钢的蠕变抗力。

Effect of Cu Contents on Microstructure and Creep Property of High Chromium Ferric Steels

The microstructure and creep property before and after creep of three high chromium ferric steels with 0wt%Cu,0.6wt%Cu and 3wt%Cu were studied under the conditions of 650 ℃ and 140 MPa.The results show that the creep fracture time increasing from 1 172 h to 1 620 h and the creep rate decreased from 2.2×10-9 s-1 to 1.2×10-9 s-1 with the Cu content increasing from 0wt% to 3wt%.The addition of Cu effectively suppressed forming high temperature δ-ferrite phase adverse to the creep property.Numerous Cu-rich phases with the size of 50-100 nm dispersedly precipitated in the matrix of the tested steel with 3wt%Cu,which could effectively restrain the motion of dislocation and thus increase the creep resistance of the steel.