Invimec's insights on hot and cold metal rolling for T-Gold 2024

Metal rolling is a fundamental step in the manufacture of semi-finished and metallic products, occurring through two main approaches: hot rolling and cold rolling. Both processes have distinct effects on the raw material, resulting in semi-finished items with unique mechanical and surface properties. In this article, we will take a closer look at the differences between these two techniques, focusing on the innovations proposed by Invimec in the industry.

Metal rolling: a process of plastic deformation

Metal rolling is a type of plastic deformation which involves permanent modifications to the worked material. The metal piece passes through rotating cylinders in rolling mills, exerting strong pressure and causing flattening, elongation, and shaping of the raw material. Used in various industries, rolling mills are employed to create semi-finished products such as wires, strips, and profiles from rounds, sheets, or billets.

Hot rolling: deformation at high temperatures

Hot rolling occurs at temperatures above the material's recrystallization point, usually between 1000 and 1300°C. At these temperatures, the metal maintains considerable plastic deformability. The process involves heating the metal in special furnaces to make it malleable, followed by passes through rolling mills to progressively reduce the thickness of the material.

Hot rolling offers good malleability but presents challenges in terms of dimensional control due to phenomena such as shrinkage, distortion, and the formation of surface oxides.

Cold rolling: excellent finish and mechanical characteristics

Cold rolling takes place at room temperature, below the material's recrystallization point. Usually, hot-rolled semi-finished products are used to achieve a finer surface finish and better mechanical characteristics. The process induces metal hardening, increasing its strength and hardness, although it carries a higher risk of breakage.

Invimec's expertise in custom cold rolling solutions

With over 60 years of experience in the industry, Invimec is a leader in the design and assembly of cold rolling mills. The range of solutions includes complete "turnkey" cold rolling plants, integrated into automated and innovative lines. Invimec's cold rolling mills offer dimensional precision and surface finish significantly superior to hot rolling mills, making them ideal for the finishing phase.

The two processes, hot and cold rolling, are often used in sequence to obtain metallic products with impeccable mechanical properties. Cold rolling, with its ability to bestow excellent mechanical characteristics and high-quality finishing, is essential for the manufacturing of precise and high-performance semi-finished products.

You can personally explore Invimec's solutions at the International Exhibition of Machinery for Goldsmith and Precious Metals, T-GOLD, in Vicenza (IT), Hall L, from January 19 to 23, 2024, booth 191. Its team of experts looks forward to welcoming you!