To improve corrosion resistance of chip ball valve by heat treatment
The method to improve the corrosion resistance of the chip ball valve is to increase the appropriate amount of stable elements Ti, Nb, Mo, etc., in order to improve the corrosion resistance and weldability. The weldability is better than that of the chromium stainless steel flange. When the chip ball valve adopts the same type of chromium stainless steel flange electrode (G302, G307), it should be preheated above 200 ℃ and tempered at about 800 ℃ after welding.
To improve corrosion resistance of chip ball valve by welding
If heat treatment is not possible, stainless steel flange pipe welding rods (A107, A207) should be used. The welding rod of the chip ball valve should be kept dry when in use. The calcium-titanium 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. , To prevent the electrode coating from sticking to oil and other dirt, so as not to increase the carbon content of the weld and affect the quality of the weldment.
