Effect of ultra-fine structure obtained by surface mechanical attrition treatment(SMAT) on microstructure, yield strength (YS), ultimate tensile strength (UTS) and microhardness of hypoeuctectoid steel have been studied in this paper. Surface alteration has been obtained by vibratory SMAT equipment with particular parameters for similar class of material. The SMAT has been carried out for different time periods such as 10, 20, 30 min. The pearlite and ferrite geometry present has been found intermixed after SMAT process. The microstructure shows a composite structure consisting of fiber/angular cementite particulates dispersed in a ferrite matrix. Thus, these structure obtained at 30 min of SMAT has significantly affected the mechanical properties. The SMAT affected layer has found to be 300µm which shows an increased Young’s modulus from 140 GPa to 246 GPa. The yield stress (YS) and ultimate tensile strength (UTS) has been increased about 6% and 22% , respectively. The surface microhardness of the material has been changed from 226±5 HV_0.3 to 405±7 HV_0.3 by SMAT, which is attributed to the grain refinement and dispersion of fine carbide particles within the matrix.

中文翻译：

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表面机械磨损对亚共晶钢组织和力学性能的影响

研究了表面机械磨损处理（SMAT）获得的超细组织对次共晶钢组织，屈服强度（YS），极限抗拉强度（UTS）和显微硬度的影响。表面振动已通过振动SMAT设备获得，具有用于类似材料类别的特定参数。SMAT已执行了不同的时间段，例如10、20、30分钟。在SMAT处理后，发现存在的珠光体和铁素体几何形状相互混合。显微组织显示出一种复合结构，由分散在铁素体基体中的纤维/角渗碳体颗粒组成。因此，在SMAT 30分钟时获得的这些结构已显着影响了机械性能。已发现受SMAT影响的层为300µm，这表明杨氏模量从140 GPa增加到246 GPa。屈服应力（YS）和极限拉伸强度（UTS）分别增加了约6％和22％。材料的表面显微硬度已从226±5 HV更改为SMAT提供的_0.3到405±7 HV _0.3，这归因于细小碳化物颗粒在基体内的细化和分散。