Overview: 

 Welding joint refers to a contact in which two or more parts need to be welded together. Or refers to joints where two or more parts are connected by welding, including welds, fusion zones and thermal impact zones. Welding joints are formed by local heating by high-temperature heat sources. The welded joint consists of welded metal, fusion zone, thermal impact zone and base metal. 

 Components and components 

 1. Weld area: After the joint metal and filling metal are melted, they are cooled and solidified at a fast speed. Weld tissue is a cast tissue crystallized from liquid metal. The grains are coarse, the components are segregated, and the tissue is not dense, but its performance can meet the requirements through reasonable control of chemical composition and welding process. 

 2. Fusion area: It is a transitional part between the molten area and the non-melted area. The chemical composition is uneven, the structure is thick, and it is often coarse overheated or coarse hardened tissue. Its performance is often the worst among welded joints. 

 3. Heat-affact zone: the area where the structure and performance change caused by the high temperature heating of the weld area. The thermal-afflict area of low-carbon steel can be divided into overheating area, positive fire area and some phase change area, among which the plasticity and toughness of the overheating area are significantly reduced, and it is the site with the worst mechanical properties in the thermal-affence area.

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.