室温下高速车轮钢断裂韧性与冲击韧性的关系

The Relationship between Fracture Toughness and Impact Toughness of High-Speed Wheel Steel at Room Temperature

通过紧凑拉伸(CT)实验,测试不同热处理条件下高速车轮钢的室温断裂韧性;在具有不同断裂韧性的CT试样上取样,制成标准夏比V型冲击试样,在室温下对冲击试样进行冲击实验,并对其断裂韧性、冲击试样的断口和显微组织进行观察和分析。结果表明:室温下该车轮钢的断裂韧性和冲击韧性呈线性关系,预裂纹加载断裂和缺口冲击断裂以解理断裂为主;车轮钢中的夹杂物主要为Ti(C,N),在室温条件下对该车轮钢的断裂韧性和冲击韧性基本没有影响。

The fracture toughness of high-speed wheel steel was measured at room temperature through compact tension(CT) specimens heat-treated with different procedures.Charpy V-notched impact specimens were made from the CT specimens with different fracture toughness,respectively.Impact tests were carried out on impact specimens at room temperature.The fracture toughness as well as the fracture surface and microstructure of impact specimens were observed and analyzed.Results show that the fracture toughness increases linearly with the increasing of impact toughness.The fracture modes of both CT specimens and impact specimens are mainly cleavage fractures.The inclusions in wheel steel mainly are Ti(C,N) which have little effect on the fracture toughness and impact toughness at room temperature.