What are the welding technical requirements for ordinary steel plates?

Low current and slow I welding speed shall be adopted as far as possible to reduce the penetration of base metal.
As the proportion of base metal melting to the first layer of weld metal is up to about 30%, low current and slow welding speed should be used as much as possible to reduce the penetration of base metal. After welding, it should be kept at 200-350 ℃ for 2-6 hours to further slow down the cooling rate, increase the plasticity and toughness, reduce the hardening tendency and eliminate the diffusing hydrogen in the joint.

After welding, stress relief heat treatment shall be carried out for weldment immediately, especially for weldment with large thickness, high rigidity structure and weldment working under severe conditions (dynamic load or impact load). After welding, the tempering temperature for stress relief is 600-650 ℃, and the temperature is kept for 1-2h, and the temperature is cooled with the furnace.

Requirements for steel plate welding:
1. According to the steel type of the structure to be welded, the welding wire is selected. For heat-resistant steel and weather resistant steel, the main consideration is to consider the same chemical composition of the weld metal and the base metal, so as to meet the requirements of heat resistance and corrosion resistance.

2. The method of hybrid plasma arc welding is adopted with lower welding current (30A-100A) and lower plasma gas flow. There is no pinhole effect.

3. According to the spot welding position corresponding to the plate thickness of the weldment, select the diameter of the welding wire to be used, determine the current value to be used, and refer to the product introduction and use experience of each manufacturer, select the welding wire brand suitable for the welding position and current.