某活塞式蓄能器在使用过程中发生爆炸，通过对收集到的蓄能器碎片进行断口及表面宏观分析、材料化学成分和力学性能分析、扫描电镜分析、物相分析和能谱分析，并应用有限元应力分析软件进行理论爆破压力计算，找出了蓄能器爆炸的原因。结果表明：爆炸系该活塞式蓄能器内所充入气体中含有氧气，当一定浓度的氧气与渗入气体侧的液压油混合后，在机械运转过程中的激发能源的作用下发生剧烈的燃烧化学反应，瞬间产生高温高压而导致蓄能器发生爆炸。

A piston accumulator exploded during operation process. The explosion reason was found by means of visual examination, chemical compositions analysis, mechanical properties testing, SEM observation, X-ray diffraction phase analysis and energy spectrum analysis, and the burst pressure of the accumulator was calculated with finite element method. The results show that oxygen was unconsciously filled in the accumulator and mixed with the hydraulic oil permeating from the liquid part to the gas part of the accumulator. When the oxygen concentration reached a certain value, under the action of exciting energy resource from the machine operation process, violent burning chemical reactions would take place and produce high temperature and pressure in a moment, which resulted in the explosion of the accumulator.