A back-calculating method for solving difficult measurement of cyclic stress-strain of the narrow brazing seam zone (less than 150 μm) at high temperature was presented based on following two types of data: the first one was cyclic stress-strain data of DZ125 alloy base metal at high temperature

which was obtained by the finite element software ABAQUS coupling user material subroutine (UMAT) embedded into Chaboche viscoplastic model;the second one was cyclic stress-strain data of brazed joints obtained by the high-temperature cycle test;after data processing and MATLAB programming

the cyclic stress-strain of the brazing seam zone at high temperature was obtained concisely.The results show that the deformation of the brazed joints at high temperature has obvious heterogeneous and localized properties

and as compared to the base alloy metal

the brazing seam zone is relatively 'soft’

and also a weak link in brazed joints which should be given adequate attention.By extension

the proposed back-calculating method provides a new way for studying the general mechanical behavior of narrow seam of the welded joint.