A substitute for tinplate developed to reduce tin usage—a low-carbon thin steel sheet with a surface plated with chromium and chromium oxide. The structure of chromium-plated thin steel sheet consists of a steel substrate, a metallic chromium layer, a hydrated chromium oxide layer, and an oil film. See Figure 2-7 and Table 2-24.
Table 2-24 Thickness, Composition, and Performance Characteristics of Each Component of Chromium-Plated Thin Steel Sheet
| Name | Thickness | Element | Performance characteristics |
|---|---|---|---|
| Oil film | 4.9~9.5mg/m² | Sebacic acid Dioctyl ester |
Rust prevention and lubrication |
| Hydrated oxidized Chromium layer | 7.2~27mg/m² | Hydrated chromium oxide | Protects the chrome layer; facilitates painting and iron printing; and prevents holes |
| Metal chromium layer | 32.3~140mg/m² | metallic chromium | Has some corrosion resistance, but is inferior to pure tin |
| Steel substrate | Canning 0.2~0.3mm | mild steel | Good processability; and the can has the necessary strength after being made |
Figure 2-7 Chrome-plated steel plate structure
1-Oil film 2-Hydrated chromium oxide layer
3—Metal chromium layer 4—Steel substrate
