1. To prevent corrosion due to heating, the welding should not be too long, which is about 20% less than that of carbon steel electrodes.
2. Stainless steel pipe fittings harden quickly after welding, which is easy to crack. If it is welded with typical stainless steel pipe fittings, it must be preheated above 300°C and slowly cooled at about 700°C after welding. If the weldments cannot be heat treated after welding, stainless steel pipe fitting electrodes should be used.
3. For stainless steel pipe fittings, to improve the corrosion resistance and weldability, an appropriate amount of invariant elements Ti, Nb, Mo, etc. are appropriately added, and the weldability is better than that of stainless steel pipe fittings. When using the same type of chromium stainless steel electrode, it should be preheated above 200 ℃ and tempered at about 800 ℃ after welding. If the weldments cannot be heat treated, chrome-nickel stainless steel electrodes should be used.
4. Stainless steel pipe fitting welding rod has exquisite corrosion resistance and oxidation resistance and is widely used in chemical, fertilizer, petroleum, and medical machinery manufacturing.
5. The coating of stainless steel pipe fittings has titanium calcium type and low hydrogen type. Titanium-calcium type can be used for AC and DC, but the penetration depth is shallow and red at the same time during AC welding, so it should be connected to DC power as much as possible.
6. Stainless steel pipe fittings have certain corrosion resistance (oxidizing acid, organic acid, cavitation), heat resistance, and wear resistance. It is usually used as a raw material for power stations, the chemical industry, petroleum, and other equipment. The weldability of stainless steel pipe fittings is poor, and attention should be paid to the welding process and the selection of suitable welding electrodes before heat treatment.
7. The electrodes should be kept dry during use. The calcium-titanium type should be dried at 150°C for 1 hour, and the low-hydrogen type should be dried at 200-250°C for 1 hour (do not dry repeatedly, otherwise the coating will easily crack and peel off). The coating sticks to oil and other dirt, so as not to increase the carbon content of the weld and affect the quality of the weldment.
8. When welding stainless steel pipe fittings, carbides are precipitated by repeated heating, which reduces corrosion resistance and mechanical properties.
Post time: Feb-03-2023