Stainless steel flange use precautions

• 2018-11-15 10:56:00　Hits: 1554

1. In order to prevent the corrosion between the eyes due to the heating of the flange cover, the welding current should not be too large, about 20% less than the carbon steel electrode, the arc should not be too long, the layer is fast cold, and the narrow weld bead is suitable.

2, the electrode should be kept dry when used, titanium calcium type should be dried at 150 ° C for 1 hour, low a hydrogen type should be dried at 200-250 ° C for 1 hour (can not be repeated repeatedly, otherwise the skin is easy to crack and peel off), to prevent The electrode coating is sticky with oil and other dirt to prevent the weld from increasing the carbon content and affecting the quality of the weldment.

3. When welding stainless steel flanged pipe fittings, it is repeatedly heated to precipitate carbides, which reduces corrosion resistance and mechanical properties.

4, chrome stainless steel flange pipe fittings after the hardening of the US standard flange is large, prone to cracks. If welding of the same type of chrome stainless steel welding rod (G202, G207) is used, it is necessary to perform preheating at 300 °C or more and slow cooling at around 700 °C after welding. If the weldment cannot be post-weld heat treated, stainless steel flanged pipe welding rods (A107, A207) should be used.

5, stainless steel flange, in order to improve corrosion resistance and weldability, appropriately increase the amount of stability elements Ti, Nb, Mo, etc., the weldability is better than the chrome stainless steel flange. When using the same type of chrome stainless steel flanged electrode (G302, G307), preheating at 200 °C or higher and tempering at around 800 °C after welding should be carried out. If the weldment cannot be heat treated, stainless steel flanged pipe welding rods (A107, A207) should be used.

6, stainless steel flange pipe fittings, butt welding flange welding rods have good corrosion resistance and oxidation resistance, widely used in chemical, fertilizer, petroleum, medical machinery manufacturing.