In the selection of hydraulic cylinder materials, it is important to pay attention to the pressure resistance performance, strength, and stiffness of the cylinder barrel component. In addition, it should be able to withstand a certain amount of work pressure for a long time without deformation or bending.
1. Cast iron
Mainly for cylinder barrels with complex shapes. If high requirements are required, ductile iron can be used, such as QT450-10, QT500-7, and QT600-3.
2. Seamless steel pipe
The blank of the cylinder is generally made of annealed cold drawn or hot-rolled seamless steel pipes. There are already semi-finished products with honing or precision machining of the inner hole on the market, and seamless steel pipes can be cut according to the required length. The materials include 20, 35, 45 steel and 27SiMn, 25Mn alloy steel. The tensile strength of V 20 # steel pipe is 355-500MPa, the tensile strength of 35 # steel pipe is ≥ 530MPa, and the tensile strength of 45 # steel pipe is not less than 600Mpa. These steel pipes have been honed or rolled to 0.4 μ M roughness requirements.
The material of the hydraulic cylinder can be selected according to the pressure of the working medium: the low-pressure cylinder can use 20 # steel pipe, and the high-pressure cylinder can use 45 # steel pipe.
According to the working conditions, for hydraulic cylinder barrels with a working temperature below -50 ℃, 35 # steel pipe or 45 # steel pipe must be used, and quenching and tempering treatment must be carried out.
Do you need welding? If you need to weld the cylinder head or flange to the cylinder, you can choose 20 # steel pipe and 35 # steel pipe, which can be mechanically pre processed and then quenched and tempered because they have better welding performance. For cylinder barrels that are not welded to other parts, use quenched and tempered 45 # steel pipes.