Why must argon arc welding be used to weld stainless steel?

Reasons for welding stainless steel by argon arc welding;

1, argon protection can isolate the adverse effects of oxygen, nitrogen and hydrogen in the air on the arc and molten pool, reduce the burning loss of alloy elements, and obtain dense, splash-free and high-quality welded joints.

2. Argon arc welding has the advantages of stable arc combustion, concentrated heat, high arc column temperature, high welding production efficiency, narrow heat affected zone, and low stress, deformation and crack tendency of welded parts.

3. Argon arc welding is open arc welding, which is convenient for operation and observation.

4, the electrode loss is small, the arc length is easy to maintain, there is no flux and coating during welding, and it is easy to realize mechanization and automation.

5. Argon arc welding can weld almost all metals, especially some refractory metals and oxidizable metals, such as magnesium, titanium, molybdenum, zirconium, aluminum and their alloys.

6, not limited by the position of weldment, all-position welding can be carried out.

Extended data:

Argon arc welding is suitable for welding oxidizable nonferrous metals and alloy steels (mainly aluminum, magnesium, titanium and their alloys and stainless steel).

Reasons why stainless steel can't be welded with carbon steel in covered electrode;

Covered electrode welding of carbon steel 1 stainless steel is easy to cause intergranular corrosion.

2. Oxides in covered electrode of carbon steel make it easier to oxidize, and the weld metal contains more oxygen, which makes the alloy elements burn more.

3. The covered electrode coating of carbon steel contains more silicon dioxide, and some silicon exists in the weld in the form of silicon dioxide inclusions, which leads to poor mechanical properties of the weld, especially lower plasticity and impact toughness than alkaline covered electrode.

4. The covered electrode coating of carbon steel contains no fluorite (CaF2), so its hydrogen removal ability is low; The weld metal has high hydrogen content, poor cold cracking resistance, low desulfurization element manganese content and poor desulfurization effect.

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