CONTINUOUS ANNEALING INSTALLATION

PURPOSE:To produce a highly corrosion resistant cold rolled steel sheet integrally from an annealing stage in production of a cold rolled and painted steel sheet for high tension drawing by providing an annealing installation and a painting installation to the same line. CONSTITUTION:A heating furnace 1, a soaking furnace 2, a quick cooling device 4, a reheating furnace 5 and a cooling zone 6 are disposed and a surface treating zone 7 is provided between the device 4 and the furnace 5 in an installation for producing, for example, a cold rolled steel sheet for drawing. The zone 7 is formed of, for example, a coater 8, a baking furnace 9 and a cooling zone 10 of a painting device and two sets of the coaters 8 are provided in the line direction to enable two coats and two bakes. An un-coiled steel sheet S is welded to the preceding steel sheet and after the steel sheet is washed, the sheet is heated in the furnaces 1, 2 and is quickly cooled and descaled by the primary cooler 4, then a paint coated film is applied thereon by the coaters 8. The coated film is then baked in the furnace 9 and is cooled, if necessary, in the cooling zone 10. After the cooled sheet is overaged in the furnace 5, the sheet is cooled down to an ordinary temp. in the zone 6 and is coiled after temper rolling and oil coating.