Overview: 

 Welded joints refer to joints that need to be welded and combined with two or more parts. It refers to joints connected by welding two or more parts, including welds, welding areas and heat-affected areas. Welded joints are formed by local heating from high-temperature heat sources. Welding joints are composed of weld metal, welding area, heat impact area and master metal. 

 Components 

 1. Weld area: After the joint metal and filled metal are melted, it is cooled and solidified at a fast speed. The weld structure is a casting structure crystallized from liquid metals. The grains are thick, the components are segregated, and the tissue is not dense. However, through reasonable control of chemical composition and welding process, its performance can meet the requirements. 

 2. Melting area: It is a transition part between the melting area and the non-melting zone. The chemical composition is uneven and the tissue is thick. It is often a thick superthermal tissue or a thick hardened tissue. Its performance is often the worst welded joint. 

 3. Heat-affected area: an area with changes in organization and performance caused by high temperature heating in the weld area. The heat-affected areas of low-carbon steel can be divided into superheating areas, positive fire zones and partial phase transition zones. Among them, the plasticity and toughness of the superheating areas are significantly reduced, and they are the worst mechanical properties in the heat-affected areas.

Each process, each facility, and each environmental constraint has its own special requirements. Therefore, Dongyan offers a comprehensive range of products covering different performance levels, pressures, different functions and different materials.