Cylinder tube is a high-precision steel pipe material processed by cold drawing or hot rolling. Featuring advantages such as no oxide layers on the inner and outer walls of the precision steel pipe, zero leakage under high pressure, high dimensional accuracy, high surface finish, no deformation during cold bending, and no cracks during flaring and flattening, it is mainly applied to manufacture pneumatic or hydraulic components such as air cylinders and hydraulic cylinders, which can be seamless pipes. The chemical components of cylinder tubes include Carbon ©, Silicon (Si), Manganese (Mn), Sulfur (S), Phosphorus (P) and Chromium (Cr).
Processing Technologies Adopted for Cylinder Tubes
Cylinder tubes adopt roller burnishing processing. Residual compressive stress remains on the surface layer after processing, which facilitates the closure of tiny surface cracks and inhibits the propagation of corrosion. This accordingly improves surface corrosion resistance and delays the initiation or expansion of fatigue cracks, thus elevating the fatigue strength of cylinder tubes. Roller burnishing forms a work-hardened layer on the processed surface, which reduces elastic and plastic deformation on the contact surfaces of friction pairs. This enhances the wear resistance of the inner wall of cylinder tubes and prevents surface burning caused by grinding. The reduced surface roughness after roller burnishing also optimizes fitting performance.
Roller burnishing is a chipless machining process. It leverages the plastic deformation of metals at room temperature to flatten microscopic irregularities on workpiece surfaces, so as to modify the surface structure, mechanical properties, shape and dimensions of workpieces. Therefore, this process can simultaneously achieve surface finishing and surface strengthening, an effect unachievable by grinding.
Tiny uneven tool marks with alternating peaks and valleys will inevitably remain on part surfaces regardless of the machining method employed.
Principle of Roller Burnishing: It is a pressure finishing process that takes advantage of the cold plastic characteristics of metals at ambient temperature. A certain pressure is exerted on the workpiece surface via burnishing tools to trigger plastic flow of the surface metal, which fills the original residual concave valleys and lowers surface roughness. The plastic deformation of the burnished surface metal leads to work hardening and grain refinement of the surface structure, forming dense fibrous structures and a residual stress layer. Hardness and strength are consequently increased, improving the wear resistance, corrosion resistance and fitting performance of workpiece surfaces. Roller burnishing is a non-cutting plastic forming process. For more technical information, please contact Yan Bing from the Technical Sales Department in Tianjin at 13*6820.7*45*60.
