Inconel718合金O形环回弹特性研究

对从Inconel718合金管材截取的O形环小试样进行了压缩回弹试验研究.试验表明,温度、加载历史和轴向尺寸对O形环回弹量无明显影响;常温下O形环回弹量随压扁度的变化在6%~30%的压扁度范围内表现为抛物递增,此时O形环密封性能良好,但当压扁度超过30%,回弹量开始递减,且试样的压缩接触面伴随出现凹陷,在600℃以上还发生坍塌.运用ANSYS的弹塑性接触分析功能,采用不同的本构模型,分别建立了二维、三维有限元网格模型,对O形环的压缩回弹过程进行了数值模拟.研究表明,ANSYS的弹塑性接触有限元方法对O形环回弹量的分析模拟结果与试验结果吻合较好.

SPRINGBACK PROPERTIES OF INCONEL718 ALLOY O-RING

To investigate the compression springback properties of Inconel718 alloy O-ring used to seal pressure vessels, a series of experiments based on small O-ring specimens cut from alloy tubes were conducted. Experimental results show that temperature, loading history and axial-length have small effects on the springback properties of the O-ring specimens. At room temperature, it is found that the springback value of an O-ring specimen increases with an increase in the compression ratio as a parabola if the compression ratio is between 6% and 30%. The sealing property of the O-ring is good in this ratio range. When the compression ratio exceeds 30%, the springback value decreases. Environmental temperature higher than 600℃ leads to the collapse of the initial contact surface of an O-ring specimen during compression test. In order to simulate the springback properties of O-ring, 2D and 3D finite element analyses were carried out with ANSYS program using different constitutive models. It is shown that the simulation results are in good agreement with the experimental results.