Here are the precautions for welding pipe fittings shared by Carbon Steel Pipe Fittings Suppliers. I hope it will be helpful to everyone.
Malleable Iron Pipe Fittings
1. In order to prevent corrosion due to heating, the welding should not be too long, 20% less than carbon steel electrode, the arc should not be too long, fast cooling between layers, and narrow welding bead is better.
2. The hardenability of pipe fittings is quicker after welding, which is easy for cracks to occur. When welding with typical pipe fittings, preheating above 300°C and slow cooling at 700°C after welding must be carried out. If the weldment cannot be subjected to post-weld heat treatment, carbon steel pipe welding rods should be used.
3. Malleable Iron Pipe Fittings, in order to improve corrosion resistance and weldability, add appropriate amount of invariable elements, and the weldability is better than stainless steel pipe fittings. When using the same typical chromium stainless steel electrode, it should be preheated above 200 ℃ and tempered at 800 ℃ after welding. If the weldment cannot be heat treated, chromium-nickel stainless steel electrode should be used.
4. Welding rods for pipe fittings have exquisite corrosion resistance and oxidation resistance, and are widely used in chemical, fertilizer, petroleum, and medical machinery manufacturing.
5. There are titanium calcium type and low hydrogen type for pipe fittings. Titanium-calcium type can be used for AC and DC, but the penetration depth is shallow during AC welding, and it is red at the same time, so it is possible to connect to a DC power supply.
6. The pipe fittings have certain functions of corrosion resistance, heat resistance and wear resistance. It is generally used as materials for the installation of power stations, chemicals, petroleum and other equipment. The weldability of the pipe fittings is poor, so you should pay attention to the welding process and choose a suitable electrode before heat treatment.
7. The electrode should be kept dry during operation. 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. Beware of sticky oil and other dirt on the electrode coating, so as not to increase the weld. The carbon content affects the quality of weldments.
8. When the pipe fittings are welded, they are repeatedly heated to precipitate carbides, which reduces corrosion resistance and mechanical performance.
The company also provides welded steel pipes and Seamless Steel Pipes, please feel free to contact us if necessary.
