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论文类型：期刊论文

发表时间：2014-08-01

发表刊物：JOURNAL OF CENTRAL SOUTH UNIVERSITY

收录刊物：SCIE、EI

卷号：21

期号：8

页面范围：3019-3023

ISSN号：2095-2899

关键字：Hastelloy C-276; vacuum hot bulge forming; creep constitutive equation; finite element method

摘要：A stress relaxation test has been carried out for Hastelloy C-276 at temperature of 800 A degrees C and initial stress level of 250 MPa. Based on the experimental stress relaxation curve, the relationship between creep strain rate and stress has been derived. Then, a set of creep constitutive equations has been built and the values of constants arising in the constitutive equations have been determined by fitting the creep strain rate-stress curve. Close agreement between computed results and experimental ones is obtained for stress relaxation data. The creep constitutive equation set has been integrated with the commercial FE (finite element) solver MSC. Marc via the user defined subroutine, CRPLAW, for the vacuum hot bulge forming process modelling of Hastelloy C-276 thin-walled cylindrical workpiece. The temperature field, the radius-direction displacement field and the stress-strain field are calculated and analyzed. Furthermore, the bulging dimension and the final internal diameter of workpiece are predicted and the test results verify the reliability of the finite element method.