Carbon steel flange

Carbon steel flange, that is, flange plate or end flange connector made of carbon steel. The flanges made of carbon steel are called carbon steel flanges. Common materials are cast carbon steel grade WCB, forging A105, or Q235B, A3, 10 #, # 20 steel, 16 manganese, 45 # steel, Q345B, etc

The carbon steel flange has two sealing surfaces, and the sealing surface material of the ball valve is widely made of various plastics, which has good sealing performance and can realize full sealing. Carbon steel flange can be used in medium with suspended solid particles due to its wiping property during opening and closing. Model Q41F-16C Q41F-25C American standard A105 is about 0.9% (the standard is 1.05Max can reach 1.65% Max with the carbon content decreasing), while the national standard 16Mn content is about 1.3% (the standard is 1.2% ～ 1.6%), and the Japanese standard S25C is less than 0.6%

As a connecting piece, carbon steel flange is mainly a device connecting carbon steel flange plate and flange end. Its connection function is specific. It is only a device connecting carbon steel flange plate and flange end

The basic process of carbon steel flange forming is: first, weld a polygonal ring shell or polygonal sector shell, close both ends, apply internal pressure, and then under the action of internal pressure, the polygonal section gradually becomes circular and finally becomes a circular ring shell

Common problems during flange processing:

I. Scratches are hard to remove:

Overall pickling and passivation will cause chemical corrosion or electrochemical corrosion to rust in the presence of corrosive medium, and impurities such as carbon steel and spatter that adhere to the stainless steel surface due to scratches and welding spatter cannot be removed

The solution is as follows:

(1) In order to weld robustly, punch a bump on the workpiece to be welded, which can make the bump contact with the flat plate evenly before power on welding, so as to ensure that all points are heated together, and the welding direction can also be confirmed together. Welding is required. The preloading time, pressure maintaining time, holding time, and rest time should be adjusted to ensure that the workpiece can spot weld robustly

(2) Select blanking, and then enter the next process. Different stainless steel workpieces enter the corresponding process according to the processing requirements

(3

II. Weld failure:

(1) The weld failure of flange is severe. If manual mechanical grinding is used to compensate, the grinding trace will form uneven surface, which will affect the beauty

(2) Uneven grinding, polishing and passivation: pickling and passivation treatment is carried out after manual grinding and polishing. It is difficult to achieve uniform treatment for workpieces with large area, and it is impossible to obtain the desired uniform surface. Also, its faults include labor cost and auxiliary material cost