By means of investigating the macroscopical and microcosmic rupture configuration, chemical composition, mechanical properties and hydrogen content of the material, it is suggested that the rupture is originated in the shatter crack.

• 通过对断口的宏观和微观形貌、材质的化学成分、力学性能、氢含量等分析，认为从动轴的断裂是由干白点造成的。