Influence of Temperature and Time of Exploitation of Welded Joints in the Operation of Static and Dynamic Loads

Shown in this paper is the analysis of the effects of exploitation duration and temperature on the measure of fracture resistance of constituents of a welded joint between new and exploited low-alloyed Cr-Mo steel A-387 Gr. B subjected to static and variable loads. Exploited parent metal is a part of a reactor mantle which was working for over 40 years and is in the damage repair stage, i.e. part of its mantle is being replaced with new material. Tensile curves necessary for stress analysis were determined, along with material strength properties and Wohler’s curves were drawn, in other words permanent dynamic strength was determined as material resistance to crack initiation, on room and working temperature. Based on test results, the analysis of fracture resistance represents the comparison of values obtained for characteristic areas of the welded joint and justifiability of the selected welding technology.