1. Core Thickness Range Differences
2. Reasons for Thickness Differences
Hot-Rolled Process Limitation: Hot rolling uses high temperatures (900–1100°C) to soften the steel, making it easy to roll thick plates. However, it cannot produce ultra-thin plates (≤3 mm) stably-thin hot-rolled plates are prone to warping, uneven thickness, and surface defects due to high-temperature deformation.
Cold-Rolled Process Advantage: Cold rolling is performed at room temperature, with the steel passing through multiple rolling passes to reduce thickness gradually. This process ensures high dimensional accuracy and surface smoothness for thin plates, but it cannot handle thick materials (≥3 mm) due to limited rolling pressure and high energy consumption.
3. Additional Performance Differences Related to Thickness
Flatness: Cold-rolled thin plates have better flatness (tolerance ≤0.1 mm/m) than hot-rolled plates, making them suitable for precision processing (e.g., laser engraving of house numbers).
Formability: Thin cold-rolled plates have higher ductility and can be bent into complex shapes without cracking; thick hot-rolled plates are more rigid, ideal for load-bearing structural parts.
Patina Formation: Hot-rolled plates have a rough surface with natural mill scale, which accelerates patina formation; cold-rolled plates have a smooth surface, requiring artificial patina acceleration to achieve uniform color.
