针对海工装备O形密封圈实际工作中海水的酸碱性和海洋特殊环境,开展O形密封圈老化加速寿命试验.基于橡胶老化经验公式与阿仑尼乌斯加速模型,设计模拟海洋环境的老化加速寿命试验台,在湿度80%、盐度35%(质量分数)、pH值8.22的环境下,开展35、50与65℃下的老化加速试验;建立丁腈橡胶密封圈老化动力学模型,分析不同温度下压缩永久变形率随时间的变化规律,以及温度与老化时间以及压缩永久变形率之间的函数关系,预测海工装备中O形密封圈使用寿命.结果表明:密封圈在相同介质中不同温度下老化时,使用寿命随着温度升高而减少的速度并无明显变化.采用建立的密封圈老化动力学模型,推测出在25~30℃海水环境下密封圈使用寿命在1~1.5年之间,与实际使用寿命基本吻合.
In view of the acidity and alkalinity of seawater in the actual operation of O-rings in marine equipment and the special marine environment,the accelerated aging life test for O-rings was carried out.A test bench for simulating the accelerated life of aging in the marine environment was designed based on the empirical formula of rubber aging and the Arrhenius acceleration model.The aging acceleration test at the temperatures of 35 ℃,50 ℃ and 65℃was carried out un-der the environment of humidity of 80%,salinity of 35%and pH of 8.22.The aging kinetic model of nitrile rubber seal ring was established,and the variation law of compression set rate with time at different temperatures,as well as the function re-lationship between temperature and aging time and compression set rate,was studied.The service life of O-ring in offshore equipment was predicted.The results show that when the sealing ring ages in the same medium and different temperature media,there is no significant change in the decreasing rate of service life with the increasing of temperature.Using the es-tablished aging kinetic model of the sealing ring,it is speculated that the service life of the sealing ring in the seawater en-vironment from 25 ℃ to 30 ℃ is between 1 and 1.5 years,which is basically consistent with the actual service life of the sealing ring.