【摘要】 根据强流脉冲电子束表面合金化的特点,建立了相应的数学物理模型,以3Cr2W8V模具材料为基体,以Al为合金化元素,对电子束照射材料表面所产的热应力进行了数值模拟,并将数值模拟分析结果与实验结果进行了对比分析,结果表明:有限元模拟显示3Cr2W8V电子束合金化Al样品(Al层厚度t=2μm)冷却后的表层4μm范围内的点残余拉应力达到材料的屈服极限750 MPa,理论上材料将发生屈服。通过金相观察,样品表面有大量熔坑形貌,但并未出现明显裂纹,说明3Cr2W8V样品表面屈服形式主要为熔坑。另外,3Cr2W8V材料表层10μm范围内主要受残余拉应力,残余拉应力大小约为650～750 MPa。随着深度的增加,残余拉应力值急剧减小,并在距离表层20μm处受最大残余压应力,最大残余压应力值约为120 MPa,并随着深度的继续增加,残余压应力值缓慢减小。更多还原

【Abstract】 Based on the characterization of high-current pulsed electron beam surface alloying,a mathematical physics model was established to describe the surface alloying process of Al coating prepared on 3Cr2W8V.Computer simulation was used to thermal stress associated with the HCPEB bombardment,and compared with the experiment result.It is shown that the surface of residual draw stress is about 750 MPa(within 4 μm of surface),it reached to the yield strength of 3Cr2W8V.It will cause bend.By metallurgical microscope,a lot of crater defects were found on the surface after alloying,but crack dosn’t occur.The result shows that the main method of bend is crater defects.Additionally,it caused residual draw stress in the surface of 10 μm,the value of residual draw stress is about 650-750 MPa.With increasing the depth of surface,the residual draw stress will decrease very quickly.When the depth of surface reached to 20 μm,the residual press stress is about 120 MPa.With increasing the depth of surface,the residual press stress will decrease slowly.更多还原