铜含量对高铬铁素体钢组织和蠕变性能的影响

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

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。

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.