一种高强韧性钢的纳米结构及其性能

以Cr—Mn—Si为主，添加其它微量元素和稀土元素，研制了一种新型的中碳低合金耐磨钢。试验结果表明，这种新型的低合金高强韧性耐磨钢，其铸态和锻态试样经淬火回火处理后均可得到回火马氏体及少量贝氏体、残留奥氏体及碳化物组织。铸态淬火回火处理的U型缺口试样的冲击韧度αk=37～55J／cm^2，无缺口试样的冲击韧度αk=210～300J／cm^2，其硬度为53～56HRC；锻后淬火回火处理的u型缺口试样的冲击韧度αk=48～70J／cm^2，其硬度为52～54HRC，抗拉强度叽=1850～2000MPa。采用高分辨电镜，对研制钢的纳米结构原子像进行了观察，确定了贝氏体铁素体亚片条的尺寸。

Nanostructural Atomic Image and Mechanical Properties of a High Strength and Toughness Steel

A novel medium carbon low alloy wear resistance steel was developed with its main composition of Cr-Mn-Si and added with other trace elements and rare earth elements.The experiment results show that the microstructures of the steel samples as-forged then quenched and tempered are tempered martensite and a small amount of bainite,retained austenite and carbide.The impact toughness of the cast samples quenched and tempered with U-notch and without notch are 3755J/cm~2 and 210300J/cm~2 respectively,and their hardness is 5356HRC;while the forged samples quenched and tempered,their hardness is 5254HRC,the impact toughness with U-notch is 4870J/cm~2,and the tensile strength _b is 18502000MPa.The nanostructure atomic image of the steel was observed under a high-resolution electron microscopy and the subplate sizes of the bainitic ferrite were determined.