贝氏体钢轨的低温疲劳裂纹扩展行为

刘蓉, 高古辉, 桂晓露, 白秉哲

Low-Temperature Fatigue Crack Propagation Behavior of Bainitic Rail Steel

LIU Rong, GAO Guhui, GUI Xiaolu, BAI Bingzhe

图9 不同∆K时贝氏体钢轨在-40 ℃下疲劳断口形貌的SEM像

Fig.9 SEM images showing the fatigue fracture surface morphologies of bainitic rail steel tested under various ΔK at -40 ^oC (BF—bainitic ferrite, PAGB—prior austenite grain boundary)
(a, b) ΔK = 9.0 MPa·m^1/2 (c, d) ΔK = 13.5 MPa·m^1/2
(e) ΔK = 16.5 MPa·m^1/2 (f) ΔK = 18.0 MPa·m^1/2
(g, h) etched fracture surface morphologies, where ΔK = 16.0-18.0 MPa·m^1/2