1., in order to prevent intercrystalline corrosion due to heating, the welding current should not be too large, less than 20% of carbon steel electrode, arc should not be too long, and interlayer fast cooling is suitable for narrow welding pass.
2. the stamping elbow is hardened after welding, and the crack is easily produced. If the same type of stainless steel stamping elbow is welded, it is necessary to preheat up to 300 degrees centigrade and slow cooling treatment at about 700 C after welding. If the weld can not be heat-treated after welding, the stainless steel stamping elbow should be selected.
3. stamping elbow, in order to improve corrosion resistance and weldability, appropriately increase the amount of non disorder elements Ti, Nb, Mo and so on, the weldability is better than the stamping elbow. When the same type of chromium stainless steel electrode is used, it should be preheated above 200 centigrade and tempering treatment at about 800 C after welding. If the welding parts can not be heat treated, the chromium nickel stainless steel electrode should be selected.
4. stamping elbow electrode has good corrosion resistance and antioxidant properties, and is widely used in chemical, chemical, chemical, petroleum, medical machinery manufacturing.
5. the skin of the stamping elbow has a titanium calcium type and a low hydrogen type. The titanium calcium type can be used for AC and DC, but the welding depth is shallow, and it is easily reddened at the same time, so the DC power is used as much as possible.
6. the stamping elbow has a certain corrosion resistance (oxidizing acid, organic acid, cavitation), heat resistant and wear-resistant function. It is usually used in power plant, chemical, petroleum and other equipment and materials. The weldability of the stamping elbow is poor. It is necessary to pay attention to the welding process, the precondition of heat treatment and the selection of suitable welding strip.
The 7. electrode should be used to keep dry, titanium calcium type by drying at 150 deg.c for 1 hours, low hydrogen by drying at 200-250 deg.c for 1 hours (not repeated drying, or medicine skin easily cracking), prevent the covering of viscous oil and other dirt, lest cause the increase of carbon content and the influence of welding seam welding quality.
When the 8. stamping elbow is welded, the carbide is precipitated by repeated heating, which reduces the corrosion resistance and mechanical function.