Stainless elbow is made of stainless steel plate (usually 304,321 stainless steel plate) as raw material. After the steel plate is cut into materials according to the requirements, it is molded, that is, punched into a circular shape by punching die, and then two identical ones are used to reassemble, weld, adjust and so on. Welds will definitely be produced during the splicing process, so heat treatment should be performed after the stainless steel plate is welded. There are two important processes in welding stainless elbows: flaw detection and heat treatment.
The outstanding performance of stainless elbow is yield strength and stress corrosion resistance. The yield strength of duplex stainless steel is nearly 1 times higher than that of austenitic stainless steel, which can save material under the same pressure level. It has a lower linear thermal expansion coefficient than austenitic stainless steel and is close to low carbon steel, which makes the connection between duplex stainless steel and carbon steel more suitable and has great engineering significance. Forging and cold stamping of duplex stainless steels is not as good as that of austenitic stainless steels. Weldability: Duplex stainless steel has good weldability, and the susceptibility to cold cracking and hot cracking is small. Usually, there is no preheating before welding and no heat treatment after welding. Due to the higher nitrogen content, the single-phase ferritization tendency of its heat-affected zone is less, and the welding material is more reasonable. When the welding line energy is properly controlled, the welding head has good comprehensive performance.
Stainless elbow is a pipe fitting that changes the direction of the pipeline. What is the elbow standard? According to the angle, there are 45°, 90°, and 180° three most commonly used. In addition, according to the needs of the project, it also includes other abnormal angle elbows such as 60°.
The materials of stainless elbow include cast iron, stainless steel, alloy steel, malleable cast iron, carbon steel, non-ferrous metals and plastics. According to the production process, it can be divided into: welding elbow, stamping elbow, push elbow, casting elbow, etc. Other names: 90-degree elbow, right-angle elbow, 180-degree stainless elbow, etc.
Stainless elbow generally refers to the diameter above 45°. Large-diameter elbows include large-diameter straight seam elbows and large-diameter seamless elbows butt welded elbows. The most used on the market is the butt welding elbow. In addition to the high technical requirements for raw materials and equipment, the straight seam and seamless seam are relatively expensive in terms of large diameters. According to the angle, large-diameter elbows can be divided into 45° large-diameter elbows, 90° large-diameter elbows, 180 degree stainless elbows and other elbows with different angles.