Cold rolled finishes apply to flat products such as sheet or coil, with thickness less than about 5mm and usually less than 3mm. They are firstly hot rolled into a strip (or cast into a slab which is hot rolled into a strip) and then cold rolled.
Cold rolling reduces the thickness by at least 50%. This smooths the surface, refines the grain structure and causes differences in the mechanical properties along and across the rolling direction. In the case of austenitic and duplex alloys, the process hardens and strengthens the stainless steel.
Finally, the steel is softened by annealing in a furnace? Each surface finish may undergo additional processes to improve the surface further. The smoother the surface finish is, the higher resistance to corrosion it will be.
|2D||No. 2D||2D||IIIb||Cold rolled, heat treated and pickled. Dull, smooth finish. Suitable for forming applications.|
|2B||No. 2B||2B||IIIc||Cold rolled, heat treated and pickled. Bright and smoother finish than 2D (obtained by skin passing or tension levelling).|
|2E||No. 2B||2E||–||Cold rolled, heat treated and mechanically descaled, may be followed by pickling. Rough and dull finish.|
|No. 4||No. 4||2G||IV||A linearly textured polished finish, one or both sides, with a typical surface roughness (Ra) of about 0.6 m.|
|SB||No. 6||2J||–||ScotchBrite finish, one or both sides, with a transverse Ra <0.5 m.|
|SSB||–||–||–||Superior ScotchBrite finish, one or both sides, with a transverse Ra <0.25 m.|
|BA||Bright Annealed Finish||2R||IIId||Cold rolled, bright annealed finish, retained by final annealing in a controlled atmosphere furnace (may be skin passed). Smooth, bright, reflective finish.|
|BE||–||–||–||Columbus 2B cold rolled, but final anneal in a controlled atmosphere furnace.|