Abstract
Stress relaxation data for some commertial steels were obtained by means of the ring method originated by Oding, and were compared with that obtained by the conventional tensile method. The date obtained by the ring method agreed with the tensile data within an error 10%, comparing the remeining stress ratio, RSR (residual stress/initial stress). This agreement, however, was imparied when the ring specimen was loaded to an initial stress greater than its yield strength. The initial stress in the ring test specimen was capable of being set to an arbitrary value to an error of less than 6% by using the unique relationship between the initial gap spacing of the ring specimen and the shape constant, A. The stress relaxation tests under an-isothermal conditions were easy to perform using the ring test method. The value of RSR in isothermal part of the test was influenced by the heating rate to reach the test temperature, within only the first 3 or 4 hours of the test.
