Intermediate Transformation Structures in Laser Weld Joints of the X80 Steel

Intermediate transformation structures in the fusion zone of a weld joint of the X80 steel plates 8 mm thick are studied. It is shown that laser welding leads to the formation of predominantly bainite structures of various types and a small fraction of martensite in the fusion zone. The microhardness measurements in different structural phases have been carried out. The fine bainite and martensite structures have been analyzed using scanning tunnel microscopy.