Tool Steels Welding

(Source: Lucchini Sidermeccanica)

Optimizing the life cycle of a tool is a common need for all users. The possibility to restore a worn mold, to modify
the geometry of a matrix or to adjust of machining errors in tool making means to manage at the best one’s production resources.
From this point of view, a correctly operated tool steel welding offers many advantages.
In spite of relevant progresses done during years of research and study of welding processes, tool steel welding operations require specific preparation and skill.
For this reason, we recommend to follow the suggested instructions in this technical sheet, without omitting the most important element: the skill and technical preparation of the welder, after verifying the improved qualification and adequate welding equipment.

Hardness and toughness of the weld joint are the most significant parameters to evaluate the success of the weld. A relevant shift of these two properties, in comparison with other properties of the base steel, could compromise the solidity of the component.

In case of welding on hot work tools, the welded areas have to exhibit the same heat resistance properties as the base steel. With an accurately chosen filler metal and with an appropriate pre- and post-welding heat treatment cycle, it is possible to have deposit material with such mechanical properties that can resist excellently to external stress.

While operating on plastic injection molds, it is necessary to choose the electrode according to finishing features required on final molded parts. In case of a photo-etched mold it is fundamental that the weld looks invisible, under pain of rejecting the molded piece: the same happens in case of a specular polished mold. We recommend to follow the operative instructions explained in this technical sheet and to use the suggested consumables.