Methods and skills of welding stainless steel with electric welding machine

Stainless steel is the abbreviation of stainless and acid-resistant steel, and the steel with weak corrosion or stainless property to air, steam and water is called stainless steel. What are the methods and skills for welding stainless steel with electric welding machine? The following is a detailed explanation for everyone.

Stainless steel welding skills (1) Manual welding (MMA): Manual welding is a very common and simple welding method in stainless steel processing. The length of the arc is adjusted by hand, depending on the gap between the electrode and the workpiece. Meanwhile, when used as an arc carrier, covered electrode is also a welding filler. This welding method is very simple and can be used to weld almost all materials processed by Hefei stainless steel. Outdoor use, good adaptability, even underwater use.

(2)MIG/MAG welding: This is an automatic gas shielded arc welding method. In this method, the arc is welded between the current-carrying wire and the workpiece under the protection of shielding gas. The welding wire fed by the machine, as covered electrode, melts under its own arc. Because of the universality and particularity of MIG/MAG welding method, it is still a relatively extensive welding method in the world.

(3)3TIG welding: Arc is generated between the refractory tungsten welding wire and the workpiece. The shielding gas used here is pure argon, and the welding wire is not charged. Welding wire can be sent manually or mechanically. There are also some special applications that do not require wire feeding.

(4) fillet weld

The edge of the connecting plate does not need finishing, the plate is seamless, and the weld metal is directly filled in the right angle or oblique angle formed by two weldments. The size of the right-angle side in the right-angle weld is called the leg size, and the size of the smaller side is expressed by hf. In order to ensure the weld quality, it is appropriate to choose the appropriate weld angle size.

(5) Butt weld

Butt weld with penetration is called butt weld. In order to facilitate the construction, ensure the construction quality and ensure that the butt weld is full of cracks on the base metal, different groove forms are adopted according to the thickness of the steel plate. When the gap is too large (3 ~ 6mm), a backing plate (arc striking plate) can be set under the V-joint, the single-sided V-joint and the I-joint to prevent the molten metal from flowing and make the root weld run through. In order to ensure the welding quality, prevent the groove at both ends of the weld and reduce the influence of stress concentration on dynamic load, after the weld is formed, both ends can be left on the weldment unless it does not affect the use, otherwise it should be removed after the welding is completed.

Main characteristics of weldability of stainless steel (1)

Different uses of products have different requirements for welding performance. A kind of tableware generally does not require welding performance, even including some pot enterprises. However, most products need good welding performance of raw materials, such as second-class tableware, thermos cups, steel pipes, water heaters, water dispensers and so on.

(2) Corrosion resistance

Most stainless steel products require good corrosion resistance, such as first-class and second-class tableware, kitchen utensils, water heaters, water dispensers and so on. Some foreign businessmen also do corrosion resistance tests on products: use NACL aqueous solution to heat to boiling, pour out the solution after a period of time, wash and dry, and weigh the weight loss to determine the degree of corrosion.

(3) Polishing performance

In today's society, stainless steel products are generally polished during production, and only a few products, such as water heaters and drinking fountains, do not need polishing. Therefore, this requires that the polishing performance of raw materials is very good.

(4) Heat resistance

Heat resistance means that stainless steel can still maintain its excellent physical and mechanical properties at high temperature.

(5) Corrosion resistance

When the number of chromium atoms in steel is not less than 12.5%, the electrode potential of steel will suddenly change from negative potential to positive potential, and electrochemical corrosion can be prevented.