The process flow of piston rod is a complex and delicate process involving multiple key steps to ensure the accuracy, quality, and performance of the final product. The following is the general process flow for piston rod machining:
1、 Material selection and preparation
Material selection: Choose alloy steel or other suitable materials with high strength and good wear resistance according to the usage environment and performance requirements of the piston rod. Common materials include 42CrMo, 35 steel, stainless steel, etc.
Material preparation: Ensure that the quality of raw materials meets production standards, and conduct necessary inspections on chemical composition, mechanical properties, and heat treatment performance.
2、 Cutting and rough machining
Cutting: Using cutting equipment to cut raw materials into bars of the required length. The cutting process should ensure that the incision is flat and free of cracks.
Rough machining: rough machining is carried out using equipment such as lathes to preliminarily form the basic shape of the piston rod. During rough machining, a machining allowance of 2-3mm is generally left on one side.
3、 Heat treatment
Quenching and tempering treatment: For raw materials with severe bending, mechanical straightening is not recommended after quenching and tempering. For bent materials, cutting is still used to change the shape of the piston rod. Quenching and tempering treatment can improve the mechanical strength and cutting performance of piston rods.
Quenching and tempering: Quenching treatment is carried out on the rough machined piston rod to improve its hardness and wear resistance. After quenching, tempering treatment is generally required to eliminate quenching stress and improve the toughness of the piston rod. The parameters of quenching and tempering (such as temperature and time) need to be adjusted according to the type and performance requirements of the material.
4、 Precision machining and surface treatment
Precision machining: The piston rod is finely machined using high-precision CNC machines and grinders to ensure its dimensional accuracy and surface quality. Precision machining includes processes such as turning and grinding. When grinding, it is important to choose the appropriate grinding wheel and fluid to reduce thermal deformation and surface burns.
Surface treatment: In order to improve the wear resistance and corrosion resistance of the piston rod, surface treatments such as chrome plating and blackening are usually required. Before chrome plating, the surface of the piston rod needs to be polished to achieve a certain roughness requirement. The thickness of the chrome plating layer is generally controlled between 0.02 and 0.05mm.
5、 Proofreading and testing
Straightening: Due to the possibility of deformation during the heat treatment process, it is generally necessary to straighten the piston rod after precision machining. Straightening can be achieved using a two roll straightening machine or a three roll straightening machine (rotary straightening), which applies sufficient bending moment to cause a certain degree of yield deformation on the surface of the piston rod, thereby achieving straightening.
Inspection: Conduct strict quality inspection on the processed piston rod, including dimension inspection, form and position tolerance inspection, surface quality inspection, etc. After passing the inspection, subsequent packaging and shipping can be carried out.
6、 Special procedures (as needed)
Deep hole machining: For certain piston rods that require deep hole machining, such as hydraulic cylinder piston rods, deep hole drilling machines and other equipment are also required for deep hole machining.
Dehydrogenation treatment: For piston rods that have undergone electroplating treatment, dehydrogenation treatment may be necessary to prevent hydrogen embrittlement.
7、 Packaging and Shipping
Packaging: Properly package the piston rods that have passed the inspection to prevent damage during transportation and storage.
Shipping: According to the customer's requirements and order information, the packaged piston rod will be shipped to the customer.
In summary, the process flow of piston rods involves multiple links and procedures, and each link requires strict control of quality and technical parameters to ensure the performance and quality of the final product.