Daily press, 2025-12-03, 05:23 pm
Hot-Rolled Steel vs. Cold-Rolled Steel
Different steel production processes naturally result in distinct steel products! Among them, hot rolling and cold rolling are the two most mainstream processes, with the following specific features:
It takes slab (mainly continuous casting slab) as raw material, which is heated and then rolled into steel strip by roughing mill train and finishing mill train. After exiting the last stand of the finishing mill, the hot steel strip is cooled to a set temperature through laminar flow cooling and then coiled into steel coils by a coiler. According to user requirements, the cooled steel coils can be processed into finished products such as steel plates, skin-pass coils, and slit steel strips through different finishing lines including skin pass, straightening, transverse/longitudinal slitting, inspection, weighing, packaging, and marking. Its core advantages are good ductility, excellent weldability, easy processing and forming, and affordable price, making it the preferred choice for most enterprises to control costs. However, it has moderate strength, a matte appearance with a slight oxide color, and weak corrosion resistance, being prone to oxidation.
It uses hot-rolled steel coil as raw material, which is pickled to remove oxide scale and then subjected to cold continuous rolling, with the finished product being hard-rolled coil. Due to work hardening caused by continuous cold deformation, the hard-rolled coil has significantly improved strength and hardness, but reduced toughness and ductility, resulting in deteriorated stamping performance. It is only suitable for parts with simple deformation. Hard-rolled coil is often used as raw material for hot-dip galvanizing plants (all hot-dip galvanizing units are equipped with annealing lines). Its core characteristics include high strength, bright and smooth surface, and better corrosion resistance than hot-rolled steel. A protective oil is applied to the surface before delivery to prevent rust (this treatment is not applied to hot-rolled steel). Its disadvantages are slightly inferior toughness and weldability, and a relatively higher price due to the more complex production process.
In summary, hot-rolled steel focuses on cost-effectiveness and versatility, while cold-rolled steel emphasizes high strength and high precision. You can select the suitable type of steel based on your budget, performance requirements, and application scenarios.
Related Reading
