Mismatched welded joints of X10CrMoVNb91 steel - beneficial and non beneficial properties

Abstract

From the point of view of damage, mismatched welded joints often used in the production of the equipment, primarily pipes, are always critical sites in the system. Very often the problem is due to welding of different types of low-alloy and high-alloy steels. The selection of additional material presents a problem since the material can match only one of the steels in the mismatched joint, usually the low-alloy one. On the other hand, the selected material determines the properties of the welded joint by controlling the metallurgical processes that lead to the development of different phases with different characteristic properties. The existing experience with welding steel X10CrMoVNb91 in mismatched joints indicates that some of the phases that are formed can have negative effects on the exploitation capability of these joints. This work considers the development of different phases during formation of joints whose one component is steel X10CrMoVNb91 that is widely used in thermal power plant equipment.