Who knows what happens when porosity appears in an argon arc weld?

1.The pre-welding cleaning is not in place.

2.The argon flow rate is not suitable.

3.Argon purity is not enough.

4.There is dirt in the nozzle.

5.The nozzle diameter is not suitable.

Causes and solutions of porosity caused by argon arc welding:

Argon arc welding is an arc welding method that uses the inert gas "argon" as the shielding gas, argon is sprayed from the nozzle to form an inert gas protective layer in the welding area, isolating the intrusion of air, so as to protect the arc and the molten pool. However, due to the weak wind resistance of argon arc welding, it is particularly sensitive to rust, water and oil pollution, and has strict requirements for gas purity, groove cleaning, welding process, etc., which is easy to produce pores. In this paper, the porosity problem caused by argon arc welding is analyzed and some solutions are proposed.

1. The influence of argon.

1.Argon is not pure.

The purity of argon is not lower when welding carbon steel, and not less than when welding aluminum, while the purity of argon used for welding titanium and titanium alloys is as high.

2.Argon flow.

The argon flow rate is too large, the gas flow rate is too fast, and the near-wall laminar flow formed when passing through the nozzle is very thin, and after the gas is sprayed out, it is quickly disordered, and it is easy to roll the air in, and the protection effect of the melt pool becomes poor. The argon flow rate is too small, and the ability to resist wind interference is weak. Therefore, the flow rate of argon must be appropriate and the airflow should be stable.

3.Air belt leakage.

Air belt interface or air belt leakage will cause the gas flow rate to be too small during welding, and the air will be sucked into the air belt, resulting in poor protection effect.

4.The effects of wind.

If the wind is slightly stronger, the argon protective layer will form a turbulent flow, resulting in poor protection. Therefore, when the wind speed is 2m s, windproof measures should be taken, and when welding the pipe, the nozzle should be blocked to avoid the formation of wind in the pipe.

5.The angle of the welding torch is too large.

If the angle of the welding torch is too large, on the one hand, it will put air into the molten pool, and on the other hand, the argon gas flow on the long arc side will be less effective in protecting the arc and the molten pool.

6.Effect of argon flow meter.

The gas outlet of the flow meter is unstable, and the protection effect will be affected by the fluctuation of large and small.

7.The effect of the welding torch nozzle.

If the diameter of the nozzle is too small, when the effective protection range of argon around the arc is less than the area of the melt pool, it will cause poor protection and porosity. Especially in field operations, large diameter nozzles should be used when welding large pipes to effectively protect the arc and melt pool.

8.The distance between the torch nozzle and the working room.

The distance is small, and the sensitivity to the influence of crosswinds is small; The distance is large, and the ability to resist wind interference is weak.

9.The cylinder pressure is too small.

When the pressure in the cylinder is less than 1MPa, it should be deactivated.

10.The impact of the operation.

When using the argon arc welding torch with control button, it is necessary to deflate before welding, so as to avoid excessive pressure in the air belt, which will cause the flow rate to be too large instantaneously and produce pores during arc initiation.

11.The welding torch fitting is not suitable.

The tungsten electrode clamp is not matched, the blocked gas path is not smooth, and the protective gas flows out from one side of the nozzle, which cannot form a complete protective ring.

Reasons for porosity in argon arc welding: 1. Air leakage of welding torch trachea; 2. The copper head in the welding torch is not good or damaged; 3. The tungsten rod is exposed too long; 4. The welding torch is far away from the mold or product; 5. The exhaust volume is too small; 6. Argon is not pure. Features of TIG welding:

1. The weld quality is high, because argon is an inert gas, it does not react chemically with metal, the alloying elements will not be burned, and argon is not melted in the metal, the welding process is basically the process of metal melting and crystallization, so the protection is better, and the weld can be obtained with purer and higher quality; 2. The welding deformation stress is small, because the arc is compressed by the argon gas flow and the cold bending reputation, the arc heat is concentrated, and the temperature of the argon arc is very high, so the heat affected zone is small, so the stress and deformation during welding are small, especially for thin parts welding and stool and pipe root welding;

Possible causes:

1. The purity of the gas does not meet the requirements. Before formal welding, test welding in the clean iron plate, do not add wire, if there are pores, you need to replace the gas.

2. The air flow is too large or too small. The size of the air flow should be adjusted according to the size of the nozzle, generally the larger the nozzle, the greater the air flow.

3. Gas turbulence. When there is a splash in the nozzle, or the tungsten chuck expands.

4. Tracheal damage. When the trachea is damaged, it will appear when the arc is started by welding or when it is formed shortly after the arc starts, and then it will return to normal.

Solution: Test welding in the cleaned iron plate before formal welding, do not add wire, if there are pores, you need to replace the gas; The air flow is too high, or too small. The size of the air flow should be adjusted according to the size of the nozzle, generally the larger the nozzle, the greater the air flow. Gas turbulence. When there is a splash in the nozzle, or the tungsten chuck expands.

There are the following reasons for the appearance of porosity in TIG welds:

1.There are impurities such as rust, paint, oil, water and other impurities on the surface of the welding wire or workpiece, and the filler material welding wire should be kept clean without impurities, and the welding area should be polished clean to expose the true color of the metal.

2.The gas is impure. The purity of argon gas for welding needs to be reached, if the purity of the gas does not meet the requirements, it will cause oxidation of the front end of the tungsten electrode in welding, and the phenomenon of porosity will occur in serious cases.

3.The gas protection effect is not good. There is strong wind and the wind speed is too large, the gas flow is too small, the gas path is blocked or the gas path is leaking, and the welding operation is not standardized.

Hello, the appearance of stomata has the following points:

1。The gas cylinder outlet joint, the welder inlet pipe and the outlet pipe joint are not tightened and leak air;

2。Broken trachea;

3。The inner diameter of the tungsten electrode clamp of the welding torch is larger than the diameter of the tungsten electrode used;

4。If the welding torch is leaking, try to change the welding gun;

5。The argon flow rate is too small, which can be increased appropriately;

6。If the quality of argon is questionable, pure argon with a purity of more than one should be used.

The gas flow is insufficient.

Argon purity is not enough.

The angle of the welding torch is incorrect.

Welding consumables cleaning work (thorough cleaning).

1. Causes of stomata

1) The weld was not cleaned in time. If not removed in time, it will cause no fusion during welding, and wrinkled skin will be formed on the surface of the weld surface or internal pores and slag inclusions will be formed on the surface of the weld, which will directly affect the welding quality.

2) The wind speed is too high when working. When the actual counterpart gap is too large, the transition layer needs to be surfacing on the bevel side of the pipeline. Set up temporary shelter facilities to strictly control the wind speed at the welding operation, because the wind speed exceeds a certain range, it is easy to produce pores.

2. Causes of cracks:

1) Arc extinguishing too fast. Arc extinguishing is different from electrode arc welding, if the arc is extinguished too quickly, it is easy to produce arc pit cracks, so the weld pool should be led to the edge or thicker part of the base metal during operation, and then gradually shrink the molten pool and slowly extinguish the arc, and finally close the shielding gas.

2) Use hot die casting mold. Hot die casting molds often have tortoiseshell cracks, most of which are caused by thermal stress, but also caused by surface oxidation or corrosion of die casting raw materials, heat treatment to adjust to appropriate hardness to improve its life, too low or too high hardness is not applicable.

Summary. Hello, the reasons for the porosity of argon arc welding: 1. The welding torch has air leakage; 2. The copper head in the welding gun is not good or damaged; 3. The tungsten rod is exposed too long; 4. The welding torch is far away from the mold or product; 5. The exhaust volume is too small; 6. Argon is not pure.

Hello, the reasons for the porosity of argon arc welding: 1. The welding torch has air leakage; 2. The copper head in the welding gun is not good or damaged; 3. The tungsten rod is exposed too long; 4. The welding torch is far away from the mold or product; 5. The exhaust volume is too small; 6. Argon is not pure.

The characteristics of argon arc welding: 1. The weld quality is high, because argon is an inert gas, it does not react chemically with metal, the alloying elements will not be burned, and argon is not melted in the metal, the welding process is basically the process of metal melting and crystallization, so the protection is better, and the weld can be obtained with purer and higher quality; 2. The welding deformation stress is small, because the arc is compressed and cooled by the argon gas flow, the arc heat is concentrated, and the temperature of the argon arc is very high, so the heat affected zone is small, so the stress and deformation during welding are small, especially for thin parts welding and pipeline root welding;

Porosity appears in the soldering iron.

Welding materials, base metal grinding and cleaning, etc. are strictly implemented in accordance with the regulations; Strengthen welder practice, improve operation level and operation experience; For welds with surface porosity, mechanical grinding is used to remove defects, and repair welding is carried out if necessary.