中文摘要：

研究了ECAP道次对Q235钢拉伸性能与位错强化的影响。结果表明,ECAP加工明显提高了钢的强度,尤其是抗拉强度,但强度并非是随着ECAP道次的增加而增加。基于XRD分析和Taylor公式的定量计算,研究了ECAP提高强度的机理。结果说明,结构细化提高的强度小于位错密度增加提高的强度,后者对强度提供的贡献至少占到50%。

英文摘要：

The effects of ECAP passes on tensile properties and dislocation strengthening of Q235 steel were studied. The results show that ECAP processing significantly improves the strength of the steel, especially yield strength. But the strength does not increase as ECAP passes increase, and the intensity peak appears in the first pass. The mechanism of increasing the strength with ECAP was studied based on the XRD analysis and quantitative calculations of Taylor formula. The research results explain that the strength increased by structure refinement is smaller than that caused by the increasing of dislocation density. And the later one contributes at least 50% in strength.