含V超高氮钢的析出行为及对力学性能的影响

Precipitation Behavior of Ultra-high Nitrogen Steel Containing V and Its Influence on Mechanical Properties

采用Thermo-Calc软件计算了含V超高氮钢的伪二元平衡相图。借助金相显微镜、扫面电子显微镜研究了含V超高氮钢的时效析出行为,并对力学性能进行了测试。结果表明,V元素的添加,使MX型氮化物在1131~1203℃之间析出;1230℃/1 h固溶处理和不同温度的时效处理不会使VN消失,且随时效温度的增加,VN尺寸有长大的趋势;Cr_(2)N相在1203℃以下逐渐析出,在900℃时效过程中Cr_(2)N含量随时效时间的延长而增多;Cr_(2)N的析出使试验钢的力学性能降低,尤其导致伸长率快速下降。

Thermo-Calc software was used to calculate the pseudo binary equilibrium phase diagram of ultra-high nitrogen steel containing V.By means of metallographic microscope and scanning electron microscope,the aging precipitation behavior of ultra-high nitrogen steel containing V was studied,and the mechanical properties were tested.The results show that the addition of V elements causes MX-type nitrides to precipitate between 1131-1203℃.1230℃/1h solution treatment and aging treatment at different temperatures make VN disappear,and as the aging temperature increases,the VN size tends to grow.The Cr_(2)N phase gradually precipitates below 1203℃,and the Cr_(2)N content increases with the increase of the aging time during the aging process at 900℃.The precipitation of Cr_(2)N reduces the mechanical properties of the test steel,especially the elongation decreases rapidly.