The impact of groove edge temperature and heat input on the structure and hardness of the heat affected zone of steel 460 NL1 welded joint

Abstract

The starting structures and cooling times in the temperature range 800–500°C (t8/5) have a decisive influence on the structures and properties of the heat-affected zone of steel welded joints. At the cooling time t8/5, inter alia, the groove edge temperature has an effect. Due to heating by the electrical arc, the groove edge temperature along the joint increases, resulting in an extension of the cooling time of the heat-affected zone. Therefore, the cooling time t 8/5 is extended along the joint. The paper presents the measurement results of the groove edges' temperature during the welding of the multilayer joint of the microalloyed steel P 460 NL1. The influence of these temperatures on the cooling time t8/5 and on the macro- and microstructure and hardness in the heat-affected zone of this welded joint was determined.