Why do pores always appear in gas shielded welding?
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Reason 1: Impure gas. Preventive measure: Clean the gas cylinder regularly; before use, invert it for 1–2 hours, open the valve to allow water to drain out, and then use it. Reason 2: Countermeasures against surface oil and rust: Clean the surface of the workpiece of oil, rust, scale, etc. before welding. It can be removed using methods such as wire brushes or shot blasting. Reason 3: Air path blockage or leakage. Preventive measure: Regularly check whether the air path system is blocked or leaking. Clean, maintain, or replace in a timely manner, and develop good operating habits. Reason 4: No vent holes in the sealed weld. Preventive measure: Increase the chamfer on the butt weld to ensure no air gaps remain in between. Leave a portion of the weld unwelded or weld it later after the workpiece has cooled down. Reason 5: The welding torch angle is too low, allowing air to enter the weld pool from the back and cause porosity. Prevention measure: Adjust the angle of the welding torch properly. Reason 6: Excessive or insufficient gas flow. Countermeasure: Adjust the flow rate of the shielding gas to meet the requirements.
The causes of pores in gas shielded welding and the corresponding preventive measures include the following: 1. **Impure gas** – **Preventive measure**: Regularly clean the gas cylinder; before use, invert it for 1–2 hours, open the valve to release water, and then use it. 2. **Surface oil and rust** - **Prevention measures**: Thoroughly clean the surface of the workpiece of oil, rust, scale, etc. before welding; methods such as wire brushing and shot blasting can be used for removal. 3. **Air path blockage or leakage** – **Prevention measures**: Regularly check whether the air path system is blocked or leaking, and clean it, maintain it, or replace it in a timely manner to develop good operating* habits. 4. **No vent holes in closed welds** – **Prevention measures**: Increase the chamfer size when performing butt welds to eliminate air gaps; leave a portion of the weld unwelded or weld it later after the workpiece has cooled down. 5. **Too small a welding torch angle** - **Prevention measures**: Adjust the welding torch angle to prevent air from entering the molten pool from behind. 6. **Excessive or insufficient gas flow** - **Prevention measures**: Adjust the flow rate of the shielding gas to ensure it meets the welding requirements. The above measures can effectively reduce or prevent the occurrence of porosity during gas shielded welding. .