Welding technique in architectural steel structures referred to the requirements of JGJ81 - 2002
Architectural steel structures refer to the structures of buildings, bridges, automobiles and ships constructed by metal materials. In terms of steel, it is the skeleton composed of various metal alloys made of metal or non-metal materials by welding, bolt connection or other methods.
Generally speaking, the welding process of steel structure is divided into non-destructive testing, welding preparation, welding, post-weld heat treatment and non-destructive testing. According to the requirements of JGJ81 - 2002, the welding method of architectural steel structure is divided into manual arc welding, gas shielded welding, submerged arc welding and other methods.
The manual arc welding technology of architectural steel structure requires that the welding rod should be used in the matching range specified in the standard and the matching ratio should be strictly controlled. The rod should be gentle, the operation requires more skill and special attention. The welder should have certain welding operation experience and obtain certain related professional qualification certificates.
Gas shielded welding is mainly used for welding butt joint and fillet joint of structural parts. Before welding, the joint should be cleared of welding slag and welding spatter, and the root of the weld should be ground. When welding, preheating, inter layer temperature control and slow cooling must be strict in accordance with the requirements of the procedure.
Submerged arc welding is mainly used for welding the butt joints and fillet joints of architectural steel structures with large welding thickness. This process has the characteristics of fast speed, stable arc, good penetration, low welding spatter and low smoke. In the welding process, it is necessary to select the appropriate flux and welding wire. The welding process of welding should also control the welding parameters including welding current, voltage and welding speed strictly, and the workpiece must be preheated.
For post-weld heat treatment, the requirements of JGJ81 - 2002 are that high temperature softening heat treatment is carried out on structural parts and components welded by welding according to requirements. After post-weld heat treatment, non-destructive testing is also necessary.
In summary, the welding process of architectural steel structure should be subject to different welding methods and related requirements such as non-destructive testing, welding preparation, welding, post-weld heat treatment and non-destructive testing according to JGJ81 - 2002. Welders should have enough technical experience and required professional certificates. In addition, the welding current, voltage and welding speed should be strictly controlled in the welding process. And the heat treatment can strengthen the welding quality of the steel structure. Finally, the non-destructive testing should be carried out to check the quality of the welded steel structure.
