Abstract
The material SA508-3 steel used for nuclear power was subjected to tensile test in six temperature levels(800~1300°C) by solidifying methods on Gleeble-1500D thermal simulation testing machine to analyze its microstructure changes. It was found that the strain, reduction in area, and thermal strength were all reached the most value at 1000°C. The fracture organization of six temperatures were the different form lath martensite. The maximum hardness of 800, 1000 and 1300°C test sample were at 10, 14 and 18 mm, respectively, and the hardness range ability of 1000°C was the lesser, the others were the larger extent. The fracture morphology of low temperature plastics was main inter granular brittle fracture, which provided the basic parameters for weld numerical simulation.