基于硬化层深均匀性激光空间能量离散相变硬化蠕墨铸铁的参数适应性和热力耦合场研究  

Study on Parameters Adaptability and Thermo-mechanical Coupling Field Based on Hardened Layer Depth Uniformity of Phase Transformation Hardening Vermicular Graphite Cast Iron with Discrete Space Energy of Laser

作　　者：庞铭 谭雯丹 冯胜强[2] 初飞雪[1] PANG Ming;TAN Wendan;FENG Shengqiang;CHU Feixue(School of Airport,Civil Aviation University of China,Tianjin 300300,China;Ningbo Branch of China Academy of Ordnance Science,Ningbo 315103,China)

机构地区：[1]中国民航大学机场学院,天津300300 [2]中国兵器科学研究院宁波分院,浙江宁波315103

出　　处：《热加工工艺》2021年第14期119-125,共7页Hot Working Technology

基　　金：国家自然科学基金项目(U1633111,51206179);国家重点研发计划项目(2018YFB1105801);中央高校基本科研业务费资助项目(201911);中央高校基本科研业务费项目(3122018D020);中国民航大学蓝天青年科研资金资助项目(201803)。

摘　　要：为了突破传统的激光整体相变硬化蠕墨铸铁表面强韧性匹配差等问题,并揭示基于离散激光相变硬化层深均匀性的热力耦合协调响应机理,构建了离散激光相变硬化蠕墨铸铁层深均匀性的热力耦合数学和物理模型。结果表明:优化离散激光在空间的能量比例可以获得均匀离散的相变硬化层深,但会导致激光辐照区域整体热压应力值与残余拉应力值提高;基于离散的激光空间功率密度分配比例只适用于特定的激光参数;伴随激光功率和激光加载时间的增加,需调大离散激光外圈光斑的能量比例以使硬化层能够得到优化,模型截面上较大残余拉应力对应的深度会随着激光参数(激光功率密度、激光加载时间)的增加而增加,激光加载区域的材料表面残余应力值会随着加载时间的延长而降低。In order to break through the problem of poor matching of strength and toughness on the surface of vermicular graphite cast iron hardened by traditional laser integral transformation hardening,and reveal the coordination response mechanism of thermo-mechanical coupling based on the depth uniformity of discrete laser transformation hardened layer,the mathematical and physical models of thermo-mechanical coupling for the depth uniformity of discrete laser transformation hardened layer of vermicular graphite cast iron were constructed.The results show that,optimizing the energy ratio in space of discrete laser can obtain uniform and discrete depth of phase transformation hardened layer,but it will lead to the increase of the overall thermal compressive stress and residual tensile stress in the laser irradiated area.The spatial power density distribution ratio based on discrete laser is only suitable for specific laser parameters.With the increase of laser power and laser loading time,it is necessary to increase the energy ratio of discrete laser outer ring spot so that the hardened layer can be optimized.The depth corresponding to the large residual tensile stress on the section of the model increases as the laser parameters(laser power density,laser loading time)increase.The residual stress value on the surface of the material in laser loading area decreases with the increase of loading time.

关 键 词：离散激光相变硬化 空间能量优化 蠕墨铸铁 热力耦合 

分 类 号：TG156.33[金属学及工艺—热处理] TG143.49[金属学及工艺—金属学]