The chemical composition of C45 precision seamless steel pipes mainly includes carbon (C) content between 0.42% and 0.50%, silicon (Si) content between 0.17% and 0.37%, manganese (Mn) content between 0.50% and 0.80%, and chromium (Cr) content not exceeding 0.25%. The precise control of these elements helps ensure their performance and quality.

In terms of heat treatment, the recommended treatment method is normalizing to 850 ℃, quenching at 840 ℃, and tempering at 600 ℃. C45 precision seamless steel pipe, as a high-quality carbon structural steel, is characterized by moderate hardness and easy cutting processing. It is commonly used to manufacture templates, tips, and guide columns in molds, but requires heat treatment to improve its performance.

For quenching and tempering treatment, it can make the parts have good comprehensive mechanical properties, suitable for important structural components such as connecting rods, bolts, gears, and shafts working under alternating loads. However, the surface hardness after tempering is low and the wear resistance is insufficient. In order to improve surface hardness, a combination of quenching and surface hardening treatment can be used.

Carbonization treatment is suitable for heavy-duty parts with surface wear resistance and core impact resistance, and its wear resistance is better than quenching and tempering+surface quenching. Through this method, the surface carbon content can reach 0.8% to 1.2%, and the core is generally between 0.1% to 0.25%, and even up to 0.35% in special cases. After heat treatment, the surface can achieve high hardness, while the core maintains low hardness and has good impact resistance.