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Precautions for welding stainless steel pipe fitting

Date:2024-04-23View:116Tags:Steel Pipe Elbow,Precision Steel Tube,Pipe Fittings

Precautions for welding stainless steel pipe fitting

1. To prevent corrosion due to heating, welding should not be too long, about 20% smaller than carbon steel electrodes. The curvature should not be too long, and the layer will cool down quickly. Narrow welding beads are preferred.

2. Stainless steel pipe fittings quickly harden and are prone to cracking after welding. When using typical stainless steel pipe fittings for welding, it is necessary to preheat above 300 ° C and slowly cool at about 700 ° C after welding. If welding cannot accept post weld heat treatment, stainless steel pipe fittings electrodes should be used.
3. Stainless steel pipe fittings are used to improve corrosion resistance and weldability, and suitable stabilizing elements such as Ti, NB, Mo, etc. are added. The weldability is better than that of stainless steel pipe fittings. When using the same type of chromium stainless steel welding rod, a speed control treatment of about 800 ℃ should be carried out after welding. If heat treatment is not possible for welding, chromium nickel stainless steel welding rods should be used.
4. Stainless steel pipe welding rods have excellent corrosion and oxidation resistance, and are widely used in the chemical industry, fertilizers, petroleum, and medical machinery manufacturing.
5. The coatings for stainless steel pipe fittings include calcium type and low hydrogen type. Calcium type can be used for both AC and DC, but during the AC welding process, the penetration depth is shallow and turns red at the same time, so please try to connect it to the DC power source as much as possible.
6. Stainless steel pipe fittings have certain corrosion resistance (oxidation acid, organic acid, cavitation), heat resistance, and wear resistance. It is usually used as equipment material for power plants, chemical industries, petroleum, etc. The welding seam of stainless steel pipe fittings is poor, so attention should be paid to the welding process and appropriate welding rods should be selected before heat treatment.
7. The welding rod should be kept dry during use. The titanium calcium type should be dried at 150 ° C for 1 hour, while the low hydrogen type should be dried at 200-250 ° C for 1 hour (not multiple times, otherwise the coating will easily crack and peel off). Pay attention to the welding rod. The coating will stick to oil and other dirt to avoid increasing the carbon content of welding and affecting the quality of welding.
When welding stainless steel pipe fittings, carbides will precipitate due to repeated heating, corrosion resistance, and mechanical properties.