高速铣削模具钢3Cr2Mo加工硬化实验分析及建模

设计了3Cr2Mo塑料模具钢的高速铣削试验方案,借助显微硬度计和X线衍射分析仪测量了铣削加工后硬化层硬度沿层深的分布,用专业数据分析软件得出洛氏硬度与X线衍射峰半高宽之间的相关性曲线,同时建立两者之间的拟合公式,再用透射电镜观察硬化层的位错结构,用位错理论分析了加工硬化的形成机理。结果表明:随着主轴转速的增大,半高宽呈减小的趋势,说明表面硬化程度随主轴转速的提高略有下降;通过洛氏硬度与半高宽间的数学模型,可以较准确地预测3Cr2Mo的硬度;利用透射电镜观察到位错密度的增加,这与半高宽的增大一致。

Experimental analysis and modeling on work hardening of 3Cr2Mo die steel by high-speed milling

High-speed milling experiment program of 3Cr2Mo plastic die steel was designed. By means of microhardness tester and X-ray diffraction analyzer,the hardness along the layer depth after milling was obtained. The correlation curve and the fitting formula between the Rockwell hardness and the half width of X-ray diffraction peak were established with professional data analysis software. The dislocation structure of the hardened layer was observed with transmission electron microscopy(TEM). And the formation mechanism of work hardening was analyzed based on dislocation theory. The results show that with the increase of spindle speed,the half width decreases. The degree of work hardening has a slight decline as spindle speed rises. The fitting formula can accurately predict 3Cr2Mo hardness. The dislocation density increase can be observed with TEM,which is consistent with the increase of the half width of the X-ray diffraction peak.