The design and manufacture of carbon steel elbow must be considered when the hardness of the carbon steel elbow, so how to improve the hardness of the carbon steel elbow? Through research we found that the carbon steel elbow need heat treatment process: carbon steel elbow heated to a certain temperature and heat preservation for a period of time, and then make it slowly cooling, called annealing. Hot bend annealing is a heat the steel to the phase change or part of the phase transition temperature, slow cooling after heat preservation heat treatment method. The purpose of annealing is to eliminate tissue defects, improve the organization make composition uniformity and fine grains, increase mechanical properties of the hot pressing elbow, reduce the residual stress.
Carbon steel elbow is widely used in petroleum, natural gas, chemical industry, water and electricity, construction and boiler pipe butt welding elbow is forming process is complicated, need according to the use of the different material and welding, gradually forming under the certain pressure.
The advantages of carbon steel elbow molding process:
1, don’t need tube billet as raw material, can cut down the cost of pipe equipment and mould, and can get any big diameter and wall thickness is relatively thin, the size of the head. The size of the head material is special, don’t need to join the pipe material, easy to control during machining.
2, does not need tube billet as raw material, can cut down the cost of pipe equipment and mould, and can get any big diameter and wall thickness is relatively thin carbon steel elbow.
3, due to the above two reasons, can shorten the manufacturing cycle, the production cost greatly reduced. Because do not need any special equipment, especially suitable for machining of carbon steel in site the size of the head.
Carbon steel elbow welding first a cross section of a polygon or both ends closed multi multi ring shell fan shell, internal filled with medium pressure, with inner pressure and internal pressure under the action of cross section of polygonal gradually became round, and eventually become a circular ring shell. According to the need of a circular ring shell can be cut into four 90 degree bend or six 60 degree elbow or other specifications of the elbow, the process is suitable for manufacturing elbow pitch diameter and any specifications of large elbow bend diameter ratio greater than 1.5, is the ideal way to make the large carbon steel elbow.
Source: Yaang Pipe Industry Co., Limited (www.yaang.com)