ABSTRACT A two diagram procedure was used to assess the microstructure effects on tensile strain hardening in different silicon strengthened ductile irons produced through different cooling rates. In the Matrix Assessment Diagram, the data from different ductile irons were identified through lines. While with Si 2.5 wt-% the intercept of the best fitting line was positive in agreement with the physical meaning of strain hardening, the intercept decreased with increasing silicon content and decreasing cooling rate, becoming unexpectedly negative with Si 4.5 wt-% and slow cooling rates. The negative intercepts were found to be related to graphite degeneracy. In the Integrity Assessment Diagram the effect of microstructure on ductility was investigated, reporting that ductility was reduced significantly by graphite degeneracy. So the two diagram procedure that was first proposed to classify ductile irons with different chemical compositions and production routes, can also indicate the presence of graphite degeneracy in ductile irons.

中文翻译：

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评估不同冷却速率生产的硅强化球墨铸铁的微观结构对拉伸行为的影响

摘要 使用两图程序来评估微观结构对通过不同冷却速率生产的不同硅强化球墨铸铁的拉伸应变硬化的影响。在矩阵评估图中，来自不同球墨铸铁的数据通过线进行识别。虽然 Si 2.5 wt-% 的最佳拟合线的截距为正值，与应变硬化的物理意义一致，但截距随着硅含量的增加和冷却速度的降低而减小，而 Si 4.5 wt-% 和缓慢冷却时截距出乎意料地变为负值率。发现负截距与石墨简并有关。在完整性评估图中，研究了微观结构对延展性的影响，报告称石墨简并显着降低了延展性。