1. Welding method
Hot rolled and normalized steels have no special requirements for welding methods and are suitable for various welding methods, such as shielded metal arc welding, submerged arc welding, electroslag welding, CO gas shielded welding, argon tungsten arc welding and resistance welding. This shall be determined according to the plant equipment conditions, product structure characteristics, welding quality requirements, production batch and other factors.
2. Welding materials
The selection of welding materials is based on:
(1) The principle of equal strength, that is, the welding material with the same strength as the base metal shall be selected, and the plasticity and toughness of the weld shall be comprehensively considered.
(2) Ensure that the weld does not have cracks, air holes and other defects.
In order to ensure the strength of weld metal and base metal, different grades of welding materials shall be selected for different plate thicknesses and groove forms. Generally speaking, when welding materials suitable for thick plate with groove are used for thin plate without groove, the strength of the weld is higher, and the plasticity and toughness are lower. It shall also be considered whether stress relief heat treatment is required after welding. For welding structures subject to stress relief heat treatment after welding, welding materials with higher strength shall be selected.
