氮含量对18Mn18CrN钢高温性能的影响

Influence of Nitrogen Content on High Temperature Properties of 18Mn18CrN Steel

通过热模拟试验研究了不同试验温度下,氮质量分数分别为0.07%、0.34%、0.44%和0.72%的18Mn18Cr N钢的断面收缩率和抗拉强度等力学性能。结果表明:(1)18Mn18Cr N钢的断面收缩率随着试验温度的升高而增大,但当温度高于1 200℃时,略有下降;(2)氮含量增加,钢具有高塑性的温度区变窄,氮质量分数为0.72%的钢,其具有最佳力学性能的温度区缩小至1 150~1 200℃;(3)随着试验温度的升高,18Mn18Cr N钢的抗拉强度均呈线性下降的趋势,且氮含量越高,其高温抗拉强度对温度的变化越敏感;(4)氮含量增加,18Mn18Cr N钢的断面收缩率呈"V"形趋势变化。

Mechanical properties such as reduction of area and tensile strength of 18Mn18CrN steels containing by weight 0.07% ,0.34% ,0.44% and 0.72% nitrogen, respectively, at different test temperatures were investigated by a thermal simulation experiment. The results were outlined as follows： （1） With the increase of test temperature, so too did the reduction of area of the 18Mn18CrN steels, but slightly reduced at temperatures over 1 200 ℃ ; （2）As the nitrogen content became higher, the temperature range in which the steels exhibited high plasticity narrowed, and the temperature range in which the 18Mn18Cr 0.72N steel possessed the optimum mechanical properties narrowed to 1 150 to 1 200℃ ; （3） With the increase of test temperature, the tensile strength of 18Mn18CrN steels decreased monotonically, and the higher nitrogen content, the more sensitive to variation in temperature the high temperature tensile strength of steels was; （4） With the increase of nitrogen content, the reduction of area of 18Mn18CrN steels changed in the form of ＂V＂.