Hot-rolled and Cold-drawn Difference

Hot-rolled steel is produced using mainly billets as raw material. The billets are heated in a roughing mill and finishing mill group made of steel. The steel strip coils are then produced by laminar cooling the steel to the set temperature and rolling it through the hot strip mill. The steel is then cooled through different finishing line processing to become flat volume and slitting steel products.

Cold drawing involves processing various types of steel at room temperature through cold-drawing, bending, and drawing. This results in a more precise and uniform product.

Hot-rolled and cold-rolled difference:

1. The hot rolling and cold drawing processes for steel or steel plate formation have a significant impact on the microstructure and mechanical properties of the resulting product. Hot rolling is the primary method used, while cold drawing is only used for small-scale and sheet production.

2. Cold-formed steel cross-sections allow for local buckling, which can fully utilize the rod bearing capacity after buckling. In contrast, hot-rolled steel does not allow for local buckling to occur.

3. Hot-rolled steel and cold-rolled steel have different residual stress, resulting in different cross-sectional distributions. The residual stress distribution of cold-formed steel is curved, while that of hot-rolled or welded steel sections is film-like.

4. Hot-rolled and cold-rolled steel differ in their torsional stiffness ratio, with the latter exhibiting better performance.

5. Hot rolling process: tube - heating - hot punch - rolling - cooling bed, cold drawing process: beginning - drill holes - pickling - phosphate - drawing - annealing.