The delaminating phenomenon is observed in fracture zone of three samples, the delaminating phenomenon of fracture of 16MnR steel is obscure, while that of Q235B steel is obvious.

• 3.；对试样断口形貌研究发现：三种材料的裂纹扩展区均出现分层现象，其中尤以Q235B为明显；16MnR 最不明显；