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通过对预充氢３１０不锈钢薄膜在透射电镜（ＴＥＭ）下的原位拉伸观察，并和不含氢试样的结果相比较，研究了氢在韧－脆转变中的作用及氢致脆断机理．结果表明，预充氢的３１０不锈钢试样在拉伸过程中从裂尖发射大量位错，平衡后形成无位错区（ＤＦＺ）；纳米级微裂纹择优在ＤＦＺ中形核；微裂纹不钝化为空洞，而是通过多个微裂纹的形核及相互连接导致裂纹的脆性扩展．即氢使奥氏体不锈钢由韧变脆的根本原因是氢抑制了ＤＦＺ中纳米级微裂纹向空洞的转化．
The effect of hydrogen on the ductile-brittle transition and hydrogen-induced brittle fracture were studied by observing the in-situ tension of the pre-hydrogenated 310 stainless steel thin film under transmission electron microscope (TEM) mechanism. The results show that a large number of dislocations are emitted from the crack tip during the pre-hydrogenation of 310 stainless steel sample, and the dislocation-free region (DFZ) is formed after the equilibration. The nano-scale microcracks preferentially nucleate in the DFZ; the microcracks are not blunt Into a hollow, but through a number of micro-crack nucleation and interconnection led to brittle fracture expansion. The fundamental reason that hydrogen makes austenitic stainless steel brittle from ductile is that hydrogen suppresses the transformation of nano-scale microcracks to cavities in DFZ.