Definition of welding parameters by cooling time in temperature range 800-500ºC

Abstract

Cooling time in the temperature range 800–500°C has a great effect on the structures that arise in the heat-affected zone of welded steel. Data on optimal cooling time t8/5 for certain steels can be found in the literature. The period of the cooling time t8/5, during the welding of the particular joints, in addition to the thickness and physical properties of welded steel, depends on the shape of the weld, the welding process, and welding parameters as well. In this work, the procedure for the selection of welding parameters for a butt joint welded to the microalloyed steel P 460 NL1 is presented. The microstructure in the heat-affected zone and the results of the measurement of their hardness are shown and analyzed. It is concluded that the welding parameters selected with the help of cooling time t8/5 provide the satisfactory structure and hardness of welds.