Q420qE桥梁钢深缺口断裂强度特性试验研究

Experimental Study on Deep Notch Fracture Characteristics of Q420qE Bridge Steel

1. Luoyang Ship Material Research Institute, Luoyang 471023, China;
2. Henan Key Laboratory of Technology and Application of Structural Materials for Ships and Marine Equipment, Luoyang 471023, China

摘要: 开展了20 mm厚Q420qE钢-80℃～+20℃下的深缺口宽板拉伸试验和标准光滑试样拉伸试验,试验结果表明:随温度的降低,光滑试样的断裂强度R_f逐步增大,断裂应变e_f基本不变,而深缺口试样的断裂强度R_n则出现明显的下降。为表征R_n与R_f、e_f及温度的相关性,提出了引入温度项的修正Neuber公式,修正后的公式计算得到的R_n值与实测值的偏差在±5%以内,这一结果表明,对于深缺口宽板拉伸试验,温度的降低可能会增大缺口引起的应力应变集中效应。
- Q420qE钢 /
- 深缺口 /
- 断裂强度
Abstract: Deep notch wide plate tensile test and conventional tensile test are conducted on 20 mm-thick Q420qE steel in temperature range of -80~20℃. Results indicate that with the decreasing temperature, the fracture strength R_f increases, the fracture strain e_f remains almost the same, and the deep notch fracture strength R_n decreases. A modified Neuber formula is proposed to describe the relationship between R_n, R_f, e_f and the temperature. The deviation between R_n calculated by the proposed formula and tested by deep notch wide plate tensile test is within ±5%, indicating that for deep notch wide plate tensile test, the decrease of temperature may increase the concentration of stress and strain due to the presence of the deep notch.
- Q420qE steel /
- deep notch /
- fracture strength

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