Hot-rolled and Cold-drawn Difference
Hot-rolled is based on the slab (mainly billet) as raw material, heated by a roughing mill and finishing mill group made of steel. From finishing the last one out of the hot strip mill by laminar cooling to the set temperature, the coiling machine rolled steel strip coils, steel roll cooled through different finishing line processing and become steel, flat volume and slitting steel products.
Cold drawing means at room temperature, after cold-drawing, bending, drawing and other cold plate or strip into the processing of various types of steel.
1, Hot rolling and cold drawn steel or steel plate forming process is the same, they have a great impact on the microstructure and mechanical properties of steel, rolled steel, hot-rolled mainly based, cold-rolled steel used only for the production of small and sheet.
2, Cold- formed steel cross-section appears to allow local buckling, which can make full use of the rod bearing capacity after buckling; while hot-rolled steel does not allow cross-section of local buckling occurs.
3, For different reasons hot-rolled steel and cold-rolled steel residual stress, so the distribution of the cross section is also very different. Cold-formed steel residual stress distribution on the cross-section is curved, and hot rolled steel or welded steel section of the residual stress distribution is a film type.
4, The freedom of hot-rolled steel cold-rolled steel high torsional stiffness ratio, so torsional performance is better than hot-rolled steel cold-rolled steel.
5, Hot rolling process: tube - heating - hot punch - rolling - cooling bed, cold drawing process: beginning - drill holes - pickling - phosphate - drawing - annealing.