应变速率和温度对10NiCrMo船体钢力学性能的影响

Effects of Strain Rate and Temperature on the Mechanical Properties of 10NiCrMo Hull Steel

  • 摘要: 探讨了高应变速率(动态)和低温对10NiCrMo船体钢拉伸力学性能的影响。拉伸试验结果表明:室温下,在应变速率较低时(1.6×10-3/s~1.6×10-1/s),随着应变速率增加,强度和塑性变化不大;而当应变速率较高时(2.8×102/s~1.2×103/s),总体上强度和塑性随应变速率的增加而有所增加,未发生脆化现象。在室温至-196℃温度范围内,常规应变速率下,抗拉强度Rm随温度的降低而增加,-196℃时的强度增加约30%;而断后伸长率随温度的降低也有增加,增加约14%,不但未出现低温脆性,而且有好于室温的塑性。但当较高应变速率和低温共同作用时,与常规拉伸试验结果相比,试验钢的强度明显增加,而塑性明显下降,下降约50%。10NiCrMo船体钢在高应变速率、低温条件下独特的力学性能与均匀变形能力和断裂机制的变化有关,材料的塑性与其断裂方式无对应关系。

     

    Abstract: Effects of high strain rate and low temperature on tensile properties of 10NiCrMo hull steel were investigated.The results of tensile test showed that high strain rate and low temperature had effects on mechanical properties of 10NiCrMo hull steel.At room temperature and lower strain rates (1.6×10-3/s~1.6×10-1/s), with increasing the strain rate, the tensile strength and plasticity of the steel had no obvious change.At higher strain rates (2.8×102/s~1.2×103/s), with increasing the strain rate, the tensile strength and plasticity increased slightly and embrittlement did not occur.At normal strain rate and from room temperature to -196 ℃, the tensile strength Rm of the steel increased with decreasing temperature, the increment of the tensile strength reached 30% at -196 ℃;and the elongation increased as well with decreasing temperature, the increment of the elongation was about 14% at -196 ℃.Not only there was no embrittlement of the steel at low temperature, but also the plasticity was better than that at room temperature.But with the coaction of high strain rate and low temperature, the tensile strength increased and the plasticity decreased (about 50%) obviously in comparison with the results of common tensile test.The unique mechanical properties of 10NiCrMo hull steel at high strain rates or low temperatures were related to its uniformed deformation capacity and the change of fracture mechanism, and there was no corresponding relationship between the plasticity and the fracture mode.

     

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