结构钢中含铜析出相的时效强化作用

观察并研究了高纯Fe-1．03wt％Cu和Fe-1．65wt％Cu合金中含铜粒子的时效析出对屈服强度的影响、析出粒子尺寸的分布、以及析出粒子对位错运动的阻碍作用。用Frank-Read强化理论分析了析出粒子与屈服强度的定量关系。结果表明，析出粒子是含有一定铁的亚稳Cu-Fe相，且具有一定的塑性变形能力，从而使得含铜钢能在高强度的前提下仍具有高塑性的特征。含铜析出粒子不是刚性粒子，因而其强化效应低于传统的刚性化合物析出粒子。但析出粒子中含较多的铁，可促使粒子体积量明显增多，因此仍能实现很高的整体强化效应。增加析出粒子中的铜含量可以提高粒子对位错运动的阻力及与之相应的屈服强度。

Ageing Strengthening Effect of Precipitates Containing Copper in Structural Steels

The influence of ageing precipitation particles containing copper on the yield strength, the size distribution of precipitates, and the blocking effect of the precipitates on dislocation slips in high purity Fe-1.03 wt% Cu and Fe-1.65 wt% Cu alloys were observed and investigated. The quantitative relationship between precipitation particles and yield strength was analyzed based on Frank-Read strengthening theory. It is found that the precipitation particles belong to a meta-stable Cu-Fe phase containing certain iron and have the ability to be deformed, which leads to a high ductility combined with high yield strength. However, the precipitation particles containing copper are not rigid particles, and therefore have lower strengthening effect than those of conventional rigidity compound particles. On the other hand, the precipitation particles containing higher iron will enhance the volume fraction of precipitates and therefore the strengthening effect. The blocking effect on dislocation slips as well as the corresponding yield strength can be increased with increasing copper content in the precipitation particles.