40Cr轴面激光熔覆Ni60数值模拟  

Numerical Simulation of Laser Cladding Ni60 on 40Cr Shaft Surface

作　　者：许明三 陈相档[1,2] 王建国 叶建华 韦铁平 XU Ming-san;CHEN Xiang-dang;WANG Jian-guo;YE Jian-hua;WEI Tie-ping(School of Mechanical and Automotive Engineering,Fujian University of Technology,Fuzhou 350118,China;Advanced Manufacturing Productivity Promotion Center of FJUT,Fujian University of Technology,Fuzhou 350118,China)

机构地区：[1]福建工程学院机械与汽车工程学院,福州350118 [2]福建工程学院先进制造生产力促进中心,福州350118

出　　处：《精密成形工程》2022年第5期134-142,共9页Journal of Netshape Forming Engineering

基　　金：国家自然科学基金(51575110);福建省自然科学基金(2020J01872)。

摘　　要：目的针对激光熔覆过程中熔池内部复杂的传热和对流现象,分析激光功率和扫描速度对熔池内部温度场、流场演变和分布的影响。方法采用双椭球热源模型,建立了40Cr轴面基体激光熔覆Ni60粉末过程的三维温度场流场数值模型,并进行试验验证。结果熔覆过程形成了近似椭球体的熔池,最高温度位于移动光斑中心偏后方,达到了2080.4 K;熔池内部金属流体形成了2个方向相反的旋流,熔池表面边缘受马兰戈尼对流的影响流速最大,达到了0.49 m/s。通过对比试验和模拟获得了熔覆层截面最高温度,最高温度最大相对误差为10.1%,数值模型具有较高的准确性。结论扫描速度对熔池存在时间和形状的影响要大于激光功率,激光功率对流场的影响大于扫描速度。研究结果为轴面激光熔覆成形提供相关理论依据。There is complex heat transfer and convection phenomena in the molten pool during laser cladding.The effects of laser power and scanning speed on the evolution and distribution of temperature field and flow field in the molten pool were analyzed.The double ellipsoid heat source model was used to establish the three-dimensional temperature field and flow field numerical model of laser cladding Ni60 powder on 40Cr shaft substrate,and the experimental verification was carried out.The results showed that an approximate ellipsoidal pool was formed during cladding.The maximum temperature is located behind the center of the moving spot,reaching 2080.4 K.The metal fluid in the molten pool formed two swirls in opposite directions,and the flow velocity at the surface edge of the molten pool was the largest under the influence of Marangoni flow,reaching 0.49 m/s.By comparing the maximum temperature of the cladding cross section obtained by the experiment and simulation,the maximum relative error of the maximum temperature was 10.1%,and the numerical simulation model had good accuracy.The effect of scanning speed on the time and shape of molten pool was greater than laser power,and the influence of laser power on the flow field was greater than that of scanning velocity.The results can provide theory for laser cladding on shaft surface.

关 键 词：轴面 激光熔覆 NI60 温度场 流场 

分 类 号：TN249[电子电信—物理电子学] TG174.4[金属学及工艺—金属表面处理]