Elastic-viscoplastic constitutive equations of K439B superalloy and thermal stress simulation during casting process  

作　　者：Da-shan Sui Yu Shan Dong-xin Wang Jun-yi Li Yao Xie Yi-qun Yang An-ping Dong Bao-de Sun 

机构地区：[1]Institute of Forming Technology&Equipment,School of Materials Science and Engineering,Shanghai Jiao Tong University,Shanghai 200030,China [2]State Key Laboratory of Special Rare Metal Materials,Northwest Rare Metal Materials Research Institute Ningxia Co.,Ltd.,Shizuishan 753000,Ningxia,China [3]Shanghai Key Laboratory of Advanced High-temperature Materials and Precision Forming,School of Materials Science and Engineering,Shanghai Jiao Tong University,Shanghai 200240,China

出　　处：《China Foundry》2023年第5期403-413,共11页中国铸造（英文版）

基　　金：supported by the National Science and Technology Major Project of China(Grant No.J2019-VI-0004-0117);the State Key Laboratory of Special Rare Metal Materials(No.SKL2021K002);Northwest Rare Metal Materials Research Institute Ningxia Co.,Ltd.

摘　　要：K439B nickel-based superalloy is a new type of high-temperature material.There is insufficient research on its constitutive equations and numerical modeling of thermal stress.Isothermal tensile experiments of K439B superalloy at different temperatures(20°C-1,000°C)and strain rates(1.33×10^(-3)s^(-1)-5.33×10^(-3)s^(-1))were performed by using a Gleeble-3800 simulator.The elastic moduli at different temperatures(20°C-650°C)were measured by resonance method.Subsequently,stress-strain curves were measured for K439B superalloy under different conditions.The elastic-viscoplastic constitutive equations were established and the correspongding parameters were solved by employing the Perzyna model.The verification results indicate that the calculated values of the constitutive equations are in good agreement with the experimental values.On this basis,the influence of process parameters on thermal stress was investigated by numerical simulation and orthogonal experimental design.The results of orthogonal experimental design reveal that the cooling mode of casting has a significant influence on the thermal stress,while pouring temperature and preheating temperature of shell mold have minimal impact.The distribution of physical fields under optimal process parameters,determined based on the orthogonal experimental design results,was simulated.The simulation results determine separately the specific positions with maximum values for effective stress,plastic strain,and displacement within the casting.The maximum stress is about 1,000.0 MPa,the plastic strain is about 0.135,and the displacement is about 1.47 mm.Moreover,the distribution states of thermal stress,strain,and displacement are closely related to the distribution of the temperature gradient and cooling rate in the casting.The research would provide a theoretical reference for exploring the stress-strain behavior and numerical modeling of the effective stress of the alloy during the casting process.

关 键 词：nickel-based superalloy investment casting Perzyna model elastic-viscoplastic thermal stress numerical simulation 

分 类 号：TG146.15[一般工业技术—材料科学与工程]