Abstract

In order to improve the work hardening capacity under low stresses and the yield strength of conventional Hadfield steels, the effects of Si on the microstructure and work hardening behavior of the Fe‒17Mn‒1.1C‒xSi steels under both quasi-static tensile and low load impact are investigated. It is shown that the increase of the Si contents remarkably improves the yield strength by 36 MPa per 1 wt% Si in the investigated steel system without significant sacrifice of ductility. The decreasing effect of Si on the stacking fault energy is strongly affected by carbon, although the variation of carbon content was small. This led to the unexpected similar stacking fault energy between 1Si and 2Si steel. With the increase of the Si contents for the steels, the critical strain for the onset of mechanical twinning was lowered, which was controlled by the cooperation between the stacking fault energy and solid solution strengthening of Si. This resulted in the earlier initiation of mechanical twins and an increase in the twin volume fraction. Therefore, the work hardening capacities under both quasi-static tensile and low load impact tests were enhanced. It was also found that the impact deformation decreased as more mechanical twins absorbed the impact energy.

Graphic Abstract

中文翻译：

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Si对Fe‒17Mn‒1.1C‒xSi高锰钢组织和加工硬化行为的影响

摘要

为了提高常规哈德菲尔德钢在低应力下的加工硬化能力和屈服强度，Si对Fe‒17Mn‒1.1C‒xSi钢在准静态拉伸和低温下的组织和加工硬化行为的影响研究负载影响。结果表明，在所研究的钢体系中，Si含量的增加显着提高了每1 wt％Si的屈服强度36 MPa，而不会显着降低延展性。尽管碳含量的变化很小，但是Si对堆垛层错能的降低作用受到碳的强烈影响。这导致了1Si和2Si钢之间出乎意料的相似堆垛层错能。随着钢中Si含量的增加，机械孪晶开始的临界应变降低，它是由堆垛层错能和固溶强化硅之间的合作控制的。这导致了机械孪生的早期产生，并且孪生体积分数增加了。因此，在准静态拉伸试验和低负荷冲击试验下的加工硬化能力均得到提高。还发现随着更多的机械孪晶吸收冲击能量，冲击变形减小。

图形摘要