10Cr9Mo1VNbN耐热钢的动态断裂韧度研究

采用自制的仪器化冲击试验机，研究了１０Ｃｒ９Ｍｏ１ＶＮｂＮ钢在７７～９２３Ｋ的冲击韧度和动态断裂韧度．结果表明：在１０Ｃｒ９Ｍｏ１ＶＮｂＮ钢下平台温度范围内，缺口试样冲击能量的绝大部分用于裂纹萌生；在韧脆转变区及上平台范围内，裂纹扩展消耗大量的能量，断口的形貌观察证实了这一点．采用带预制疲劳裂纹的夏比冲击试样的示波冲击试验，可以测量材料的动态断裂韧度，并且它比冲击韧度能更敏感地反映材料脆性断裂趋势．动态断裂韧度值的变化与延伸带宽度、启裂区宽度和启裂区内韧窝尺寸有相同的趋势

Study on Dynamic Fracture Toughnessof 10Cr 9Mo1VNbN Heat-Resistant Steel

Impact resistance and dynamic fracture toughness of 10Cr9Mo1VNbN steel is investigated using instrumented impact machine over a broad range of temperatures from 77 K to 923 K. Results show that nearly all of the impact energy is consumed for crack initiation in the lower shelf range. In the ductile to brittle transition region and upper shelf range, the energy consumed during crack propagation is much higher than that during initiation. Dynamic fracture toughness K Id , which can be found from instrumented impact test of PCVN specimens, reflects brittle behavior of 10Cr9Mo1VNbN steel being more sensitive than impact resistance. The change of K Id is associated with that of stretched zone width, initiation zone width and dimple size.