| In recent years welding technique has been developed noticeably and is used widely in the field of ship building, machine production, pressure vessels, bridge construction and nuclear pressure vessels. Welded structures usually contain residual stresses due to differential contraction between weld metal and base metal. It is recognized that these stresses can lower resistance to brittle fracture by supplying additional energy to a rapidly spreading crack. Stress relief annealing treatment is used after welding process in order to release the residual stress and improve the mechanical properties of the weldments. In this paper, authors conducted the annealing treatment for the weldments in several degrees and inspected their mechanical properties and residual stresses. The results obtained in these tests are as follows: 1) The modulus of elasticity become more closer to the mean value as the annealing temperature is increased. 2) Tensile stress of the weldment is decreased 34% compared to the base metal, and as the annealing temperature is increased the tensile stress shows a little lower values. 3) The impact value seems to be decreased as the modulus of elasticity is increased in the welded zone. 4) Deviations on hardness are greater in the heat affected zone than other parts of the weldment and stabilized as the annealing temperature is increased. 5) The residual stresses are released noticeably in the vicinity of the annealing temperature around 600℃. |
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