In MIG always used filler materials, while TIG welding may or may not use. The best properties of the welded joint in terms of strength, corrosion and no cracks were obtained when using these materials.
There is no general rule for the choice of filler material due to the type of use and the parameter that more interested in each case. The high magnesium content AlMg give greater strength, while that of AlSi is more resistant to cracking and provides better flow of metal during the melting process of hardenable alloys.
Such alloys (AlCu - AlMgSi - AlZn), should not be welding filler metal alloy in the same group by the cracking process. In the event that the material is to be anodized after welding, material should be avoided because it will catch AlSi filler in the weld area very dark.
To reduce the risk of stress corrosion and increasing resistance has been added Cu alloys AlZnMg. Doing this also worsens the weldability. Several studies point out that you can add a maximum 0.2% Cu, before the danger of hot cracking increases considerably. Is chosen in this case the AlSi.
CLEANING BEFORE WELDING
cleaning prior to welding is essential to achieve good results. Dirt, oil, grease, moisture and oxides should be removed beforehand, either by mechanical or chemical. For normal work workshop can choose the following procedure: 1,
Removing dirt and cold degreasing with alcohol or acetone.
2 º Wash with water and dry immediately to avoid the risk of oxidation. Mechanical removal
3 º by:
- Brushed steel with a rotating brush.
- scraping with abrasive sand or lime.
- By blasting.
When most demanding requirements regarding the preparation, you can perform a chemical cleaning schedule is as follows:
- Removal of dirt.
- Degreasing with PERC at 121 ° C.
- Washing with water and dried immediately.
- Elimination of aluminum oxide as follows:
- Cleaning alkaline NaOH.
- Acid cleaning with HCl + HF + HNO.
- Washing with water and dried immediately.
- Neutralization with HNO (after treatment with NaOH).
- Bath in deionized water.
- Instant drying with hot air.
should never be dispensed with rust removal or degreasing in the welding area, but sometimes generates a high cost.
There is no general rule for the choice of filler material due to the type of use and the parameter that more interested in each case. The high magnesium content AlMg give greater strength, while that of AlSi is more resistant to cracking and provides better flow of metal during the melting process of hardenable alloys.
Such alloys (AlCu - AlMgSi - AlZn), should not be welding filler metal alloy in the same group by the cracking process. In the event that the material is to be anodized after welding, material should be avoided because it will catch AlSi filler in the weld area very dark.
To reduce the risk of stress corrosion and increasing resistance has been added Cu alloys AlZnMg. Doing this also worsens the weldability. Several studies point out that you can add a maximum 0.2% Cu, before the danger of hot cracking increases considerably. Is chosen in this case the AlSi.
CLEANING BEFORE WELDING
cleaning prior to welding is essential to achieve good results. Dirt, oil, grease, moisture and oxides should be removed beforehand, either by mechanical or chemical. For normal work workshop can choose the following procedure: 1,
Removing dirt and cold degreasing with alcohol or acetone.
2 º Wash with water and dry immediately to avoid the risk of oxidation. Mechanical removal
3 º by:
- Brushed steel with a rotating brush.
- scraping with abrasive sand or lime.
- By blasting.
When most demanding requirements regarding the preparation, you can perform a chemical cleaning schedule is as follows:
- Removal of dirt.
- Degreasing with PERC at 121 ° C.
- Washing with water and dried immediately.
- Elimination of aluminum oxide as follows:
- Cleaning alkaline NaOH.
- Acid cleaning with HCl + HF + HNO.
- Washing with water and dried immediately.
- Neutralization with HNO (after treatment with NaOH).
- Bath in deionized water.
- Instant drying with hot air.
should never be dispensed with rust removal or degreasing in the welding area, but sometimes generates a high cost.
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