稀土元素Ce对K-52合金高温拉伸性能的影响

Effect of Rare Earth Cerium on Hot Tensile Properties of K-52 Alloy

利用Gp-Ts20 000M热模拟机对添加稀土元素Ce的K-52奥氏体耐热钢在常温(25℃)、300℃、500℃和700℃下,以2 mm/min的拉伸速度进行拉伸试验。通过分析试样的宏观变形、力学性能变化曲线和断口形貌等,研究了稀土元素Ce对试验钢高温拉伸性能的影响,并分析其断裂机理。结果表明,随着拉伸温度的提高,金属有向塑性变形转变的趋势;试验钢中添加稀土元素Ce后,提高了合金的高温力学性能,其拉伸断口中的韧窝数量增多。与未添加稀土元素的合金相比,添加稀土元素Ce的K-52合金其屈服强度、抗拉强度和伸长率分别提高了5.37%、11.69%和22.82%。

The high temperature tensile tests of austenitic heat-resistant steel with rare earth Ce addition were conducted by using the Gp-Ts 20 000 M Universal material testing machine at the tensile rate of 2mm/min and at normal temperature(25 ℃), 300 ℃, 500 ℃, 700 ℃, respectively. The effect of rare earth element Ce on the tensile properties of the experimental steel at high temperatures was studied by analyzing the macroscopic deformation, variation curves of mechanical properties, and fracture morphology of the tensile samples. The fracture mechanism was discussed. The research results show that the experimental steels tend to exhibit plastic deformation as the tensile temperature increases. The addition of rare earth Ce increases the number of precipitates in the experimental steel, thus significantly improving the high temperature mechanical properties of the steel. The number of dimples was also increased in the fracture of the tensile samples. Compared with the alloy without the rare earth element Ce, the yield strength and tensile strength of the alloy with Ce addition increase by an average of 5.37% and 11.69%, respectively, while the elongation increases by an average of 22.82%.