10CrMo910 electric scale elbow

The electric standard seamless hot-bending elbow is mainly used in boiler pipelines, thermal power plants and other pipeline systems. With the continuous increase of the capacity of the electric installation unit, the design of the main steam and other steam-water pipelines is getting thicker and thicker, and the thickness is much higher than 70mm. Traditional pipe welding operations cannot meet the needs of factory piping. Therefore, the welding process of thick-walled elbows must be improved. Take the thick-walled elbow of P91 steel as an example, pre-weld preheating and interlayer temperature tracking. According to the analysis of the welding performance of P91, the preheating temperature before welding and the temperature of the weld layer must be strictly controlled. The preheating temperature of TIG welding is selected from 100 to 150 °C, and the temperature of SMAW is raised to 250 to 300 °C. An infrared thermometer monitors the temperature between the weld layers. When welding, it is protected by argon. Due to the high alloy content of P91 steel, the molten iron has poor fluidity and the roots are easily burnt. Argon gas can fully protect the molten metal pool from oxidation and improve the mechanical properties of the weld. A simple argon-filling device is prepared according to the actual situation before welding, and a gas chamber is formed inside the pipeline to ensure the quality of the welded joint of the thick-walled elbow. P91 molten iron has poor fluidity, so the weld of thick-walled elbows can easily form slag inclusions. The site is cleaned with an angle grinder. Do not use a hammer or tweezers to strike hard to avoid cracks. In addition, according to the requirements of the "welding regulations": welds with a wall thickness greater than 70 m must be tested in layers. When the thickness of the weld is 20~25mm, the welding is stopped, and the post-heat treatment such as heat preservation is immediately performed. After the RT test is passed, the welding is continuously performed.

The electric standard seamless hot bending elbow is often used in the bending part of the pipe to change the course of the pipe. Commonly used are 45° elbows and 90° elbows. A bending radius of about 1.0 times the outer diameter of the pipe is called a short radius elbow; about 1.5 times the outer diameter of the pipe is called a long radius elbow. When the piping system is arranged, it is generally preferred to use long-radius elbow connections. Short-radius elbows are usually used in places where the piping system is installed in a compact position or in order to reduce costs. When using a short radius elbow, its * working pressure should generally not exceed 0.8 times the long radius elbow of the same specification. Elbows are typically used on low pressure (design pressure s 2.0 MPa), water, and large-scale pipes with similar fluid conditions. When the single-section variable direction angle of the miter elbow is greater than 45, it should not be used for toxic, flammable medium pipelines, or subjected to vibration, pressure pulsation and pipelines that generate alternating loads due to temperature changes. Product process standards and quality control: feed - physicochemical - blanking - hot forging - heat treatment - inspection - gold processing - finished product inspection - identification - finished product inspection - identification - packaging typing - shipping.

The electric standard seamless hot bending elbow is suitable for gas, liquid and steam. It is widely used in various large projects such as petroleum, chemical, electric, construction and water conservancy. The product quality meets the standards of high-pressure pipe fittings for export and national execution products.