Although stainless steel flanges have unique advantages in terms of material, no matter how good they are, they still need to be used with caution, so that they can be used for a longer period.
So what should you know about the specific use of stainless steel flanges?
1. To prevent eye-to-eye corrosion due to heating of the flange cover, the welding current should not be too large, which is about 20% less than that of carbon steel electrodes. The arc should not be too long, and the interlayers will cool quickly. A narrow weld bead is preferred.
2. The welding rod should be kept dry when used. The titanium-calcium type should be dried at 150°C for 1 hour, and the low-a hydrogen type should be dried at 200-250°C for 1 hour (cannot be dried multiple times, otherwise the coating will easily cracking and peel) to prevent The coating of the welding rod is stuck with oil and other dirt, so as not to increase the carbon content of the weld and affect the quality of the weldment.
3. When welding stainless steel flange pipe fittings, carbides will precipitate due to repeated heating, reducing corrosion resistance and mechanical properties.
4. The hardened American standard flange after welding of chromium stainless steel flange pipe fittings is larger and prone to cracks. If the same type of chromium stainless steel electrode (G202, G207) is used for welding, preheating above 300°C and slow cooling at about 700°C after welding must be carried out. If the weldment cannot be subjected to post-weld heat treatment, stainless steel flange pipe fitting welding rods (A107, A207) should be used.
5. Stainless steel flange, to improve the corrosion resistance and weldability, appropriate amounts of stabilizing elements Ti, Nb, Mo, etc. are added. The weldability is better than that of chromium stainless steel flange. When using the same type of chromium stainless steel flange welding rod (G302, G307), preheating above 200°C and tempering treatment at about 800°C after welding should be carried out. If the weldment cannot be heat treated, stainless steel flange pipe fitting welding rods (A107, A207) should be used.
The above is a brief introduction to the use of stainless steel flanges, but the specific use process may be more complicated and depends on the situation.
Post time: Jan-03-2024