Computer simulation of the yield strength evolution in Cu-precipitation strengthened ferritic steel
Computer simulation of the yield strength evolution in Cu-precipitation strengthened ferritic steel
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DOI：
10.1016/j.msea.2010.02.032
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发表时间：
2010-06
期刊：
影响因子：
6.4
通讯作者：
I. Holzer;E. Kozeschnik
中科院分区：
文献类型：
--
作者：
I. Holzer;E. Kozeschnik
在含有少量 Cu 的钢的时效过程中，在 500–550°C 左右退火数小时后，可以观察到硬度和强度的最大增加。这种强度的增加是由直径为 2-3nm 的小连贯 bcc-Cu 沉淀引起的。为了对沉淀的早期阶段进行一致的计算机模拟，结果表明必须考虑 bcc-Cu 核的平衡 Fe 含量的变化。将模拟降水参数与文献报道的实验数据进行比较。在铜沉淀物的相分数、数密度和平均半径的演变方面，实验和模拟之间可以实现良好的一致性。基于这些结果，评估了不同的沉淀强化模型，并将其预测与实验观察到的强度演变进行了比较。我们发现，相干应变和模量强化效应主要有助于沉淀强化潜力。结合合金的固有强度和 Cu 固溶强化，对 Fe-1.4% Cu 合金沉淀硬化过程中较低屈服强度的演变进行了一致的描述。
During ageing of steel containing a few percent Cu, a maximum increase of hardness and strength can be observed after several hours of annealing at around 500–550°C. This strength increase is caused by small coherent bcc-Cu-precipitates of 2–3nm diameter. For consistent computer simulations of the early stages of precipitation, it is shown that variations in the equilibrium Fe-content of the bcc-Cu nuclei must be taken into account. The simulated precipitation parameters are compared to experimental data reported in literature. Good agreement between experiment and simulation can be achieved in terms of the evolution of phase fraction, number density and mean radius of the Cu-precipitates. Based on these results, different models for precipitation strengthening are assessed and their predictions compared to the experimentally observed strength evolution. We find that mainly the coherency strain and modulus strengthening effects contribute to the precipitation strengthening potential. Together with the intrinsic strength of the alloy and Cu solid-solution strengthening, a consistent description of the lower yield strength evolution during precipitation hardening of an Fe–1.4% Cu alloy is achieved.